Flexible circuit structures including connection arrangement connected to load measurement lead

ABSTRACT

Some aspects of this disclosure generally are related to improving the robustness of a flexible circuit structure, for example, by providing fault-tolerant electrical pathways for flow of electric current through the flexible circuit structure. In some embodiments, such fault tolerance is enhanced by way of a conductive mesh provided between an adjacent pair of resistive elements. Some aspects are related to improved voltage, current, or voltage and current measurement associated with various pairs of adjacent resistive elements at least when the various pairs have differing distances between them.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/445,685, filed Jun. 19, 2019, which is a continuation of U.S. patentapplication Ser. No. 16/260,704, filed Jan. 29, 2019, now U.S. Pat. No.10,375,827, issued on Aug. 6, 2019, which is a continuation of U.S.patent application Ser. No. 16/019,702, filed Jun. 27, 2018, now U.S.Pat. No. 10,231,328, issued on Mar. 12, 2019, which is a continuation ofU.S. patent application Ser. No. 15/862,010, filed Jan. 4, 2018, nowU.S. Pat. No. 10,028,376, issued on Jul. 17, 2018, which is acontinuation of U.S. patent application Ser. No. 15/366,422, filed onDec. 1, 2016, now U.S. Pat. No. 9,894,756, issued on Feb. 13, 2018,which claims the benefit of U.S. Provisional Application No. 62/264,366,filed Dec. 8, 2015, the entire disclosure of each of the applicationscited in this paragraph is hereby incorporated herein by reference.

TECHNICAL FIELD

Some aspects of this disclosure generally are related to improving therobustness of flexible circuit structures.

BACKGROUND

Cardiac surgery was initially undertaken using highly invasive openprocedures. A sternotomy, which is a type of incision in the center ofthe chest that separates the sternum was typically employed to allowaccess to the heart. In the past several decades, more and more cardiacoperations are performed using intravascular or percutaneous techniques,where access to inner organs or other tissue is gained via a catheter.

Intravascular or percutaneous procedures benefit patients by reducingrisk, complications and recovery time. However, the use of intravascularor percutaneous technologies also raises some particular challenges.Medical devices used in intravascular or percutaneous procedures need tobe deployed via catheter systems which significantly increase thecomplexity of the device structure. As well, doctors do not have directvisual contact with the medical devices once the devices are positionedwithin the body.

One example of where intravascular or percutaneous medical techniqueshave been employed is in the treatment of a heart disorder called atrialfibrillation. Atrial fibrillation is a disorder in which spuriouselectrical signals cause an irregular heartbeat. Atrial fibrillation hasbeen treated with open heart methods using a technique known as the“Cox-Maze procedure”. During this procedure, physicians create specificpatterns of lesions in the left and right atria to block various pathstaken by the spurious electrical signals. Such lesions were originallycreated using incisions, but are now typically created by ablating thetissue with various techniques including radio-frequency (RF) energy,microwave energy, laser energy, electroporation and cryogenictechniques.

Various catheter-based devices are employed to intravascularly orpercutaneously deliver (or sometimes through naturally occurring bodilyorifices) various transducers along typically tortuous paths within abody. Recently, catheters employing flexible printed circuits have beensuccessfully deployed in human patients. Flexible printed circuits allowfor the economical manufacture of various transducers and theirassociated circuitry while providing a relatively small compact sizethat is desirable for percutaneous or intravascular procedures. This isespecially important as the desire for increasing numbers of transducersincreases. For example, catheters employing several hundreds oftransducers have been produced by the applicant using flexible printedtechniques.

The present inventors recognized that the stiffness of various portionsof the flexible circuit structures may vary based on a number offactors. In this regard, the present inventors recognized that certainportions of the flexible circuit structure, such as the transducers, maybe stiffer than other portions of the flexible structure, such as theconductors. The present inventors recognized that the spatial density ofcircuitry components in the various portions of the flexible circuitstructure can affect the stiffness of these portions. For example, thepresent inventors recognized that portions of the flexible circuitstructure corresponding to the transducers may have more conductivematerial than portions of the flexible circuit structure formingconductive elements connecting the transducers, resulting in thetransducer portions being stiffer than the conductive element portions.In percutaneous or intravascular procedures, where the flexible circuitstructure is delivered through a catheter, the present inventorsrecognized that the flexible circuit structure undergoes flexing as itmoves through the body, for example, as it follows the natural contoursof a bodily path such as a vascular vessel. Due to varying stiffness,the present inventors recognized that it is possible for variousconductive elements (e.g., traces) of the flexible circuit to develop acrack due to stress forces imparted to the structure by the flexing. Thepresent inventors also recognized that flexing may occur during atransition from a delivery configuration to an expanded or deployedconfiguration in some cases. The present inventors recognized thatcracks may occur in a boundary region between a portion of the flexiblecircuit structure having relatively higher stiffness and a portion ofthe flexible circuit structure having relatively lower stiffness due tostress concentration effects. The present inventors recognized thatcracks can lead to an open circuit rendering all or parts of the circuitunusable.

In this regard, the present inventors recognized that there is a needfor at least flexible printed circuits that provide circuitry withenhanced durability and robustness suitable to withstand the rigors ofpercutaneous or intravascular delivery of the flexible printed circuitsalong tortuous bodily paths.

SUMMARY

At least the above-discussed need is addressed and technical solutionsare achieved by various embodiments described in this disclosure. Insome embodiments, flexible circuit structures are provided, the flexiblecircuit structures including circuitry exhibiting enhanced robustnessand durability, especially during flexing required by applications suchas, but not limited to, intravascular or percutaneous delivery ofcatheter devices employing said flexible printed structures. In someembodiments, the system or systems, or a portion thereof, may bepercutaneously or intravascularly delivered to position varioustransducers provided by flexible printed circuit structures described inthis disclosure within the bodily cavity. Various ones of thetransducers may be used to treat tissue within a bodily cavity.Treatment may include tissue ablation by way of non-limiting example.Various ones of the transducers may be used to map tissue within thebodily cavity. Mapping may include mapping electrophysiological activityby way of non-limiting example. Mapping may be employed in a diagnosisof various conditions. Various ones of the transducers may be used tomeasure temperature within the bodily cavity. Various ones of thetransducers may be used to stimulate tissue within the bodily cavity.Stimulation may include pacing by way of non-limiting example. Othercharacteristics and advantages will become apparent from the teachingsherein to those of ordinary skill in the art. In some embodiments, aflexible circuit structure may be summarized as including anelectrically-nonconductive substrate, and at least oneelectrically-conductive flexible circuit layer coupled, directly orindirectly, to the substrate. The at least one electrically-conductiveflexible circuit layer includes conductive patterns including: aplurality of resistive elements, each resistive element providing atleast part of a respective one of a plurality of transducers; and aplurality of conductive meshes. According to various embodiments, eachconductive mesh of the plurality of conductive meshes electricallyconnects at least a respective adjacent pair of resistive elements ofthe plurality of resistive elements, According to various embodiments,the plurality of conductive meshes serially electrically connects theplurality of resistive elements to provide at least one electric currentflow path through the plurality of resistive elements.

In some embodiments, each conductive mesh of the plurality of conductivemeshes may include a plurality of electrical connection points to eachresistive element of the respective adjacent pair of resistive elements.In some embodiments, each conductive mesh of the plurality of conductivemeshes may include a plurality of electrical pathways between theresistive elements of each respective adjacent pair of resistiveelements, and each conductive mesh of the plurality of conductive meshesmay include a plurality of electrical connection points, each electricalconnection point electrically connecting at least two of the pluralityof electrical pathways between the resistive elements of the respectiveadjacent pair of resistive elements.

In some embodiments, each conductive mesh of the plurality of conductivemeshes may include a plurality of conductive segments spatially arrangedto provide a plurality of electrical pathways between the resistiveelements of the respective adjacent pair of resistive elements, and eachconductive segment of the plurality of conductive segments providing arespective portion of each of at least some of the plurality ofelectrical pathways. In some embodiments, each conductive mesh of theplurality of conductive meshes may include a plurality of electricalconnection points electrically connecting at least two of the pluralityof conductive segments to one of the resistive elements of therespective adjacent pair of resistive elements. In some embodiments, atleast one of the plurality of electrical connection points of at least afirst conductive mesh of the plurality of conductive meshes may belocated at least adjacent one resistive element of the respectiveadjacent pair of resistive elements and may be electrically connected toat least two of the plurality of electrical connection points associatedwith the first conductive mesh located at least adjacent the otherresistive element of the respective adjacent pair of resistive elements,the at least two of the plurality of electrical connection points notincluding any electrical connection point of the at least one of theplurality of electrical connection points. In some embodiments, at leastone of the plurality of electrical connection points of at least a firstconductive mesh of the plurality of conductive meshes may be locatedcloser to one of the respective adjacent pairs of resistive elementsthan at least two of the plurality of electrical connection pointsassociated with the first conductive mesh, and the at least one of theplurality of electrical connection points may be electrically connectedto the at least two of the plurality of electrical connection points.

In some embodiments, each conductive mesh of the plurality of conductivemeshes may include a plurality of conductive segments spatially arrangedto provide a plurality of electrical pathways between the resistiveelements of the respective adjacent pair of resistive elements, and eachconductive segment of the plurality of conductive segments providing arespective portion of each of at least some of the plurality ofelectrical pathways. In some embodiments, each conductive mesh of theplurality of conductive meshes may include a plurality of electricalconnection points electrically connecting at least two of the pluralityof conductive segments to one of the resistive element of the respectiveadjacent pair of resistive elements. In some embodiments, the pluralityof electrical connection points of each of at least a first conductivemesh of the plurality of conductive meshes may include a respectivefirst electrical connection point set at least adjacent one resistiveelement of the respective adjacent pair of resistive elements and arespective second electrical connection point set at least adjacent theother resistive element of the respective adjacent pair of resistiveelements, the second electrical connection point set not including anyelectrical connection point of the first electrical connection pointset. In some embodiments, a total of the plurality of electricalpathways provided by the plurality of conductive segments of the firstconductive mesh may exceed a total of the respective first electricalconnection point set of the first conductive mesh, and may exceed atotal of the respective second electrical connection point set of thefirst conductive mesh. In some embodiments, the respective firstelectrical connection point set of the first conductive mesh, therespective second electrical connection point set of the firstconductive mesh, or each of the respective first electrical connectionpoint set of the first conductive mesh and the respective secondelectrical connection point set of the first conductive mesh includes atleast two electrical connection points.

In some embodiments, each conductive mesh of the plurality of conductivemeshes may include a plurality of conductive segments spatially arrangedto provide a plurality of electrical pathways between the resistiveelements of the respective adjacent pair of resistive elements, and eachconductive segment of the plurality of conductive segments providing arespective portion of each of at least some of the plurality ofelectrical pathways. In some embodiments, each conductive mesh of theplurality of conductive meshes may include a plurality of electricalconnection points electrically connecting at least two of the pluralityof conductive segments to one of the resistive element of the respectiveadjacent pair of resistive elements. In some embodiments, the pluralityof electrical connection points of each conductive mesh of the pluralityof conductive meshes may include a respective first electricalconnection point set at least adjacent one resistive element of therespective adjacent pair of resistive elements and a respective secondelectrical connection point set at least adjacent the other resistiveelement of the respective adjacent pair of resistive elements, thesecond electrical connection point set not including any electricalconnection point of the first electrical connection point set. Accordingto some embodiments, for each of at least a first conductive mesh of theplurality of conductive meshes, at least a first one of the plurality ofconductive segments of the first conductive mesh may extend along a pathextending from a particular electrical connection point in therespective first electrical connection point set to a particularelectrical connection point in the respective second electricalconnection point set, the path arranged to avoid intersection along thepath between the first one of the plurality of conductive segments ofthe first conductive mesh and any other one of the plurality ofconductive segments of the first conductive mesh.

In some embodiments, the plurality of electrical connection points ofeach conductive mesh of the plurality of conductive meshes may include arespective first electrical connection point set at least adjacent oneresistive element of the respective adjacent pair of resistive elementsand a respective second electrical connection point set at leastadjacent the other resistive element of the respective adjacent pair ofresistive elements, the second electrical connection point set notincluding any electrical connection point of the first electricalconnection point set. According to some embodiments, for each of atleast a first conductive mesh of the plurality of conductive meshes,each electrical pathway of at least some of the respective plurality ofelectrical pathways does not have a conductive segment in common withany other electrical pathway of the respective plurality of electricalpathways.

In some embodiments, the plurality of electrical connection points ofeach conductive mesh of the plurality of conductive meshes may include arespective first electrical connection point set at least adjacent oneresistive element of the respective adjacent pair of resistive elementsand a respective second electrical connection point set at leastadjacent the other resistive element of the respective adjacent pair ofresistive elements, the second electrical connection point set notincluding any electrical connection point of the first electricalconnection point set. According to some embodiments, for each of atleast a first conductive mesh of the plurality of conductive meshes, afirst electrical pathway of the respective plurality of electricalpathways extends from a particular electrical connection point in thefirst electrical connection point set to a particular electricalconnection point in the second electrical connection point set through asingle one of the plurality of conductive segments of the firstconductive mesh.

In some embodiments, the plurality of electrical connection points ofeach conductive mesh of the plurality of conductive meshes may include arespective first electrical connection point set at least adjacent oneresistive element of the respective adjacent pair of resistive elementsand a respective second electrical connection point set at leastadjacent the other resistive element of the respective adjacent pair ofresistive elements, the second electrical connection point set notincluding any electrical connection point of the first electricalconnection point set. According to some embodiments, for each of atleast a first conductive mesh of the plurality of conductive meshes, atleast a first group of the plurality of conductive segments of the firstconductive mesh are arranged in a branched arrangement extending from aparticular electrical connection point in the respective firstelectrical connection point set to each of at least two particularelectrical connection points in the respective second electricalconnection point set.

In some embodiments, each conductive mesh of the plurality of conductivemeshes may include a plurality of conductive segments spatially arrangedto provide a plurality of electrical pathways between the resistiveelements of the respective adjacent pair of resistive elements, and eachconductive segment of the plurality of conductive segments providing arespective portion of each of at least some of the plurality ofelectrical pathways. In some embodiments, the plurality of conductivesegments of at least a first conductive mesh of the plurality ofconductive meshes may include a first conductive segment set and asecond conductive segment set, each segment in the first conductivesegment set extending in a first direction and each segment in thesecond conductive segment set extending in a second direction, the firstdirection being perpendicular or oblique to the second direction, and atleast one of the conductive segments in the first conductive segment setintersecting with at least one of the conductive segments in the secondconductive segment set. In some embodiments, for each of at least afirst conductive mesh of the plurality of conductive meshes, each of atleast some of the plurality of conductive segments of the firstconductive mesh may be arranged to provide an unbranched pathwayextending continuously between a first resistive element of therespective adjacent pair of resistive elements and a second resistiveelement of the respective adjacent pair of resistive elements. In someembodiments, for each of a least a first conductive mesh of theplurality of conductive meshes, at least some of the plurality ofconductive segments of the first conductive mesh may be arranged toprovide a branched pathway extending continuously between a firstresistive element of the respective adjacent pair of resistive elementsand a second resistive element of the respective adjacent pair ofresistive elements.

According to some embodiments, each conductive mesh of at least some ofthe plurality of conductive meshes may electrically connect therespective adjacent pair of resistive elements via a respectiveplurality of conductive segments, each conductive segment of at leastsome of the respective plurality of conductive segments not contactingany other conductive segment of the respective plurality of conductivesegments in a region spanning an edge of a first resistive element ofthe respective adjacent pair of resistive elements and an edge of asecond resistive element of the respective adjacent pair of resistiveelements.

In some embodiments, each conductive mesh of at least some of theplurality of conductive meshes electrically may connect the respectiveadjacent pair of resistive elements via a respective plurality ofconductive segments, each conductive segment of at least some of therespective plurality of segments arranged to provide an unbranchedpathway extending continuously between a first resistive element of therespective adjacent pair of resistive elements and a second resistiveelement of the respective adjacent pair of resistive elements. In someembodiments, each conductive mesh of at least some of the plurality ofconductive meshes electrically connects the respective adjacent pair ofresistive elements via a respective plurality of conductive segments,and a group of at least some of the respective plurality of conductivesegments may be arranged to provide a branched pathway extendingcontinuously between a first resistive element of the respectiveadjacent pair of resistive elements and a second resistive element ofthe respective adjacent pair of resistive elements.

In some embodiments, each conductive mesh of the plurality of conductivemeshes may include a first electrical connection point set located atleast adjacent a first resistive element of the respective adjacent pairof resistive elements and a second electrical connection point setlocated at least adjacent a second resistive element of the respectiveadjacent pair of resistive elements. According to various embodiments,each conductive mesh of the plurality of conductive meshes mayelectrically connect the respective adjacent pair of resistive elementsvia a respective plurality of electrical pathways electrically connectedto a respective pair of electrical connections points of a plurality ofpairs of electrical connection points, each respective pair ofelectrical connection points of the respective plurality of pairs ofelectrical connection points including a respective first electricalconnection point from the first electrical connection point set and arespective second electrical connection point from the second electricalconnection point set. In some embodiments, each respective pair ofelectrical connection points of the respective plurality of pairs ofelectrical connection points may be different than every other pair ofelectrical connection points of the respective plurality of pairs ofelectrical connection points.

In some embodiments, the electrically nonconductive substrate mayinclude a plurality of electrically nonconductive layers, and the atleast one electrically-conductive flexible circuit layer may include aplurality of electrically-conductive flexible circuit layers that areinterleaved with the plurality of electrically nonconductive layers. Insome embodiments, the plurality of resistive elements may be temperaturesensors. The at least one electrically-conductive flexible circuit layermay include a plurality of electrically-conductive flexible circuitlayers, and each of at least some of the plurality of conductive meshesmay electrically connect at least a respective adjacent pair oftemperature sensors of the temperature sensors by at least one viaarranged to electrically connect different ones of the electricallyconductive flexible circuit layers.

In some embodiments, the at least one electrically-conductive flexiblecircuit layer may include a plurality of electrically-conductiveflexible circuit layers, and at least a first one of the plurality ofelectrically-conductive flexible circuit layers may include anelectrode. At least a second one of the plurality ofelectrically-conductive flexible circuit layers may include at least oneresistive element of the plurality of resistive elements and at leastone conductive mesh of the plurality of conductive meshes. In someembodiments, at least a portion of the one conductive mesh of theplurality of conductive meshes may spatially overlap at least a portionof the electrode or may be spatially overlapped by at least a portion ofthe electrode.

In some embodiments, the flexible circuit structure may include aplurality of measurement leads electrically connected to a measurementcircuit, respective pairs of measurement leads of the plurality ofmeasurement leads positioned to sense voltage across, or current flowingthrough each resistive element of each of at least some of the pluralityof resistive elements. According to some embodiments, each of theplurality of measurement leads may be electrically connected to acorresponding conductive mesh of the plurality of conductive meshes. Insome embodiments, at least one of the plurality of measurement leads mayelectrically connect to one conductive mesh of the plurality ofconductive meshes at a plurality of electrical connection points.According to some embodiments, a first measurement lead of the pluralityof measurement leads electrically connects to a first conductive mesh ofthe plurality of conductive meshes at a first electrical connectionpoint set, and a second measurement lead of the plurality of measurementleads electrically connects to a second conductive mesh of the pluralityof conductive meshes at a second electrical connection point set, thesecond set comprising a greater number of electrical connection pointsthan the first set.

In some embodiments, each resistive element may include a serpentineform.

In some embodiments, each conductive mesh of at least some of theplurality of conductive meshes may electrically connect the respectiveadjacent pair of resistive elements via a respective plurality ofelectrical pathways, at least part of one electrical pathway of at leastsome of the respective plurality of electrical pathways prevented frommerging with at least part of another electrical pathway of the at leastsome of the respective plurality of electrical pathways by a region ofelectrically-nonconductive material located between the at least part ofthe one electrical pathway and the at least part of the anotherelectrical pathway.

In some embodiments, each conductive mesh of the plurality of conductivemeshes may include a plurality of conductive segments spatially arrangedto provide a plurality of electrical pathways between the resistiveelements of the respective adjacent pair of resistive elements, and eachconductive segment of the plurality of conductive segments providing arespective portion of each of at least some of the plurality ofelectrical pathways. According to some embodiments, for each of at leasta first conductive mesh of the plurality of conductive meshes, theplurality of conductive segments of the first conductive mesh may bearranged to, at least in part, form a plurality of openings, eachopening of the plurality of openings surrounding a respective region ofthe electrically-nonconductive substrate. In some embodiments, the firstconductive mesh may extend along a first direction from a firstresistive element of the respective adjacent pair of resistive elementstoward a second resistive element of the respective adjacent pair ofresistive elements, and at least a first group of the plurality ofopenings may be arranged along one of the first direction and a seconddirection, the second direction orthogonal to the first direction. Insome embodiments, at least a second group of the plurality of openingsmay be arranged along the other of the one of the first direction andthe second direction. In some embodiments, the first and the secondgroups of openings may share at least one opening of the plurality ofopenings.

Various flexible circuit structures may include combinations and subsetsof all the flexible circuit structures summarized above.

In some embodiments, a flexible circuit structure may be summarized asincluding at least one nonconductive flexible layer including anelectrically insulative material, and one or more conductive flexiblecircuit layers proximate the at least one nonconductive flexible layer,each of the one or more conductive flexible circuit layers including anelectrically conductive material. According to various embodiments, theone or more conductive flexible circuit layers includes or include aplurality of electrical loads electrically connected in series by aplurality of electrical-connection-arrangements, eachelectrical-connection-arrangement electrically connecting a respectiveadjacent pair of electrical loads of the plurality of electrical loads;and a plurality of electrical-load-measurement leads, each electricallyconnected to at least one of the plurality of electrical loads. In someembodiments, a first electrical-connection-arrangement of the pluralityof electrical-connection-arrangements spans a first distance between afirst respective adjacent pair of electrical loads of the plurality ofelectrical loads, and a second electrical-connection arrangement of theplurality of electrical-connection-arrangements spans a second distancebetween a second respective adjacent pair of electrical loads of theplurality of electrical loads. According to some embodiments, the firstelectrical-connection-arrangement may be electrically connected to atleast one of the plurality of electrical-load-measurement leads, and thesecond electrical-connection-arrangement may be electrically connectedto a greater number of the plurality of electrical-load-measurementleads than the number of the plurality of electrical-load-measurementleads connected to by the first electrical-connection-arrangement. Invarious embodiments, each of the plurality of loads provides at least aportion of a respective one of a plurality of transducers. In variousembodiments, each of the plurality of transducers is patterned on or inthe flexible circuit structure.

In some embodiments, the first distance and the second distance may bedifferent. In some embodiments, the second distance may be greater thanthe first distance. In some embodiments, an electrical resistance of thesecond electrical-connection-arrangement may be greater than anelectrical resistance of the first electrical-connection-arrangement. Insome embodiments, the second distance may be greater than the firstdistance and an electrical resistance of the secondelectrical-connection-arrangement may be greater than an electricalresistance of the first electrical-connection-arrangement.

In some embodiments, at least the firstelectrical-connection-arrangement or the secondelectrical-connection-arrangement may include one or more conductivemeshes, each conductive mesh including a plurality of conductivesegments spatially arranged to provide a plurality of electricalpathways defining a respective portion of an electric current flow path,the respective portion of the electric current flow path located betweenthe electrical loads of the respective adjacent pair of electricalloads, and each conductive segment of the plurality of conductivesegments providing a respective portion of the plurality of electricalpathways.

In some embodiments, each of the first electrical-connection-arrangementand the second electrical-connection-arrangement may include one or moreconductive meshes, each conductive mesh including a plurality ofconductive segments spatially arranged to provide a plurality ofelectrical pathways between the electrical loads of the respectiveadjacent pair of electrical loads, and each conductive segment of theplurality of conductive segments providing a respective portion of eachof at least some of the plurality of electrical pathways. A total of theconductive meshes comprised by the secondelectrical-connection-arrangement may be greater than a total of theconductive meshes comprised by the firstelectrical-connection-arrangement according to various embodiments.

In some embodiments, each of the first electrical-connection-arrangementand the second electrical-connection-arrangement may include arespective one or more conductive meshes, each conductive mesh includinga plurality of conductive segments spatially arranged to provide aplurality of electrical pathways between the electrical loads of therespective adjacent pair of electrical loads, and each conductivesegment of the plurality of conductive segments providing a respectiveportion of each of at least some of the plurality of electricalpathways. Each conductive mesh may be directly connected to a respectiveone of a set of the plurality of measurement leads according to variousembodiments.

In some embodiments, the at least one nonconductive flexible layer mayinclude a plurality of nonconductive flexible layers, and the one ormore conductive flexible circuit layers may include a plurality ofconductive flexible circuit layers that are interleaved with theplurality of electrically nonconductive flexible layers.

In some embodiments, the plurality of electrical loads may betemperature sensors. According to various embodiments, the one or moreconductive flexible circuit layers may include a plurality of conductiveflexible circuit layers, and at least the firstelectrical-connection-arrangement or the secondelectrical-connection-arrangement may electrically connect at least arespective adjacent pair of temperature sensors of the temperaturesensors by at least one via arranged to electrically connect differentones of the plurality of conductive flexible circuit layers.

In some embodiments, each electrical load of the plurality of electricalloads may be provided at least in part by a respective one of aplurality of temperature sensors.

Various flexible circuit structures may include combinations and subsetsof all the flexible circuit structures summarized above.

In some embodiments, a flexible circuit structure may be summarized asincluding at least one nonconductive flexible layer including anelectrically insulative material, and one or more conductive flexiblecircuit layers proximate the at least one nonconductive flexible layer,the one or more conductive flexible circuit layers including anelectrically conductive material. According to various embodiments, theone or more conductive flexible circuit layers includes or include anelectric-serial-circuitry-connection-arrangement including aserial-electrical-connection order of: a firstelectrical-load-measurement lead, a first electrical load, a secondelectrical-load-measurement lead, a third-electrical-load-measurementlead, a second electrical load, a fourth-electrical-load-measurementlead, a third electrical load, and a fifth-electrical-load-measurementlead. In various embodiments, a first distance between the firstelectrical load and the second electrical load is greater than adistance between the second electrical load and the third electricalload. In various embodiments, the first electrical-load-measurement leadand the second electrical-load-measurement lead may be positioned tosense voltage across, or current flowing through the first electricalload. In various embodiments, the third electrical-load-measurement leadand the fourth electrical-load-measurement lead may be positioned tosense voltage across, or current flowing through, the second electricalload. In various embodiments, the fourth electrical-load-measurementlead and the fifth electrical-load-measurement lead may be positioned tosense voltage across, or current flowing through, the third electricalload. In various embodiments, each of the plurality of loads provides atleast a portion of a respective one of a plurality of transducers. Invarious embodiments, each of the plurality of transducers is patternedon or in the flexible circuit structure.

Various flexible circuit structures may include combinations and subsetsof all the flexible circuit structures summarized above.

In some embodiments, a flexible circuit structure may be summarized asincluding at least one nonconductive flexible layer including anelectrically insulative material, and one or more conductive flexiblecircuit layers proximate the at least one nonconductive flexible layer,the one or more conductive flexible circuit layers including anelectrically conductive material. According to various embodiments, theone or more conductive flexible circuit layers includes or include aplurality of electrical loads electrically connected in series, and aplurality of electrical-load-measurement leads, each electricallyconnected to at least one of the plurality of electrical loads.According to various embodiments, a first pair of leads of the pluralityof electrical-load-measurement leads may be positioned to sense voltageacross, or current flowing through, a first electrical load of theplurality of electrical loads. According to various embodiments, asecond pair of leads of the plurality of electrical-load-measurementleads may be positioned to sense voltage across, or current flowingthrough, a second electrical load of the plurality of electrical loads.According to various embodiments, a third pair of leads of the pluralityof electrical-load-measurement leads may be positioned to sense voltageacross, or current flowing through, a third electrical load of theplurality of electrical loads. According to various embodiments, thefirst electrical load is adjacent the second electrical load in theseries, and the second electrical load and the third electrical load areadjacent in the series. According to various embodiments, the first pairof leads and the second pair of leads share a same one of the pluralityof electrical-load-measurement leads. According to various embodiments,the second pair of leads does not share any of the plurality ofelectrical-load-measurement leads with the third pair of leads. Invarious embodiments, each of the plurality of loads provides at least aportion of a respective one of a plurality of transducers. In variousembodiments, each of the plurality of transducers is patterned on or inthe flexible circuit structure.

In some embodiments, a distance spanning the first electrical load andthe second electrical load may be different than a distance spanning thesecond electrical load and the third electrical load. In someembodiments, a distance spanning the second electrical load and thethird electrical load may be greater than a distance spanning the firstelectrical load and the second electrical load.

In some embodiments, an electrical resistance of a portion of theflexible circuit structure that serially electrically connects the firstelectrical load to the second electrical load may be different than anelectrical resistance of a portion of the flexible circuit structurethat serially electrically connects the second electrical load to thethird electrical load. In some embodiments, an electrical resistance ofa portion of the flexible circuit structure that serially electricallyconnects the second electrical load to the third electrical load may begreater than an electrical resistance of a portion of the flexiblecircuit structure that serially electrically connects the firstelectrical load to the second electrical load.

In some embodiments, the flexible circuit structure may further includea plurality of electrical-connection-arrangements, eachelectrical-connection-arrangement electrically connecting a respectiveadjacent pair of electrical loads of the plurality of electrical loads.According to various embodiments, each of at least some of the pluralityof electrical-connection-arrangements may include a set of one or moreconductive meshes, each conductive mesh including a plurality ofconductive segments spatially arranged to provide a plurality ofelectrical pathways defining a respective portion of an electric currentflow path, the respective portion of the electric current flow pathlocated between the electrical loads of the respective adjacent pair ofelectrical loads, and each conductive segment of the plurality ofconductive segments providing a respective portion of the plurality ofelectrical pathways. In some embodiments, each conductive mesh may bedirectly connected to a respective one or more of the plurality ofmeasurement leads. In some embodiments, a firstelectrical-connection-arrangement of the at least some of the pluralityof electrical-connection-arrangements may electrically connect the firstelectrical load and the second electrical load, and a secondelectrical-connection-arrangement of the at least some of the pluralityof electrical-connection-arrangements may electrically connect thesecond electrical load and the third electrical load. A total of theconductive meshes comprised by the secondelectrical-connection-arrangement may be greater than a total of theconductive meshes comprised by the firstelectrical-connection-arrangement according to some embodiments.

In some embodiments, the at least one nonconductive flexible layer mayinclude a plurality of nonconductive flexible layers, and the one ormore conductive flexible circuit layers may include a plurality ofconductive flexible circuit layers that are interleaved with theplurality of electrically nonconductive flexible layers.

In some embodiments, the flexible circuit structure may further includea plurality of electrical-connection-arrangements, eachelectrical-connection-arrangement electrically connecting a respectiveadjacent pair of electrical loads of the plurality of electrical loads.In some embodiments, the plurality of electrical loads may betemperature sensors. In some embodiments, the one or more conductiveflexible circuit layers may include a plurality of conductive flexiblecircuit layers, and at least a first one of the plurality ofelectrical-connection-arrangements may electrically connect at least arespective adjacent pair of temperature sensors of the temperaturesensors by at least one via arranged to electrically connect differentones of the electrically conductive flexible circuit layers. In someembodiments, the first one of the plurality ofelectrical-connection-arrangements may electrically connect therespective adjacent pair of temperature sensors corresponding to thefirst electrical load and the second electrical load.

In some embodiments, each electrical load of the plurality of electricalloads may be provided at least in part by a respective one of aplurality of temperature sensors.

Various flexible circuit structures may include combinations and subsetsof all the flexible circuit structures summarized above.

BRIEF DESCRIPTION OF THE DRAWINGS

It is to be understood that the attached drawings are for purposes ofillustrating aspects of various embodiments and may include elementsthat are not to scale.

FIG. 1 is a schematic representation of a medical device systemaccording to various example embodiments, where the medical devicesystem may include a data processing device system, an input-outputdevice system, and a memory device system, according to someembodiments.

FIG. 2 is a cutaway diagram of a heart and a transducer-based devicesystem percutaneously placed in a left atrium of the heart according tovarious example embodiments, the transducer-based device systemoptionally being part of the input-output device system of FIG. 1,according to some embodiments.

FIG. 3A is a partially schematic representation of a medical devicesystem, which may represent one or more implementations of the medicaldevice system of FIG. 1 in which an expandable structure of atransducer-based device system is in a delivery or unexpandedconfiguration, according to various example embodiments.

FIG. 3B is the representation of the medical device system of FIG. 3Awith the expandable structure shown in a deployed or expandedconfiguration, according to some embodiments.

FIG. 4 is a schematic representation of a transducer-based device thatincludes a flexible circuit structure, according to various exampleembodiments.

FIG. 5 is a schematic representation of a flexible circuit structurethat includes a patterned conductive layer, according to various exampleembodiments.

FIG. 6 is a schematic representation of a conductive mesh that includesa plurality of conductive segments, according to various exampleembodiments.

FIG. 7 is a schematic representation of a conductive mesh that providesa plurality of electrical pathways, according to various exampleembodiments.

FIG. 8 is a schematic representation of another conductive mesh thatprovides a plurality of electrical pathways, according to variousexample embodiments.

FIGS. 9A and 9B are schematic representations of conductive meshes,according to various example embodiments.

FIG. 10 is a schematic representation of a conductive mesh withopenings, according to various example embodiments.

FIG. 11 is a schematic representation of a flexible circuit structurethat includes a patterned conductive layer, according to various exampleembodiments.

FIG. 12 is a schematic representation of a flexible circuit structurethat includes a patterned conductive layer, according to various exampleembodiments.

FIG. 13 is a schematic representation of a flexible circuit structurethat includes a patterned conductive layer, according to various exampleembodiments.

FIG. 14 is a schematic representation of a portion of a prior artflexible circuit structure.

FIG. 15 is a schematic representation of a transducer-based device thatincludes a flexible circuit.

FIG. 16 is a block diagram of an electrical circuit configured todetermine an electrical resistance of various resistive elementsemployed by various transducers according to some embodiments.

DETAILED DESCRIPTION

Some embodiments of the present invention pertain to flexible circuitstructures including flexible conductive and nonconductive layers. Theflexible circuit structures can be subject to strain due to movement(e.g., bending, flexing) of various flexible layers comprised by theflexible circuit structures. This may result in cracks in variousconductive layers, which can lead to an open circuit or an otherwiseimpaired circuit. Cracks may also occur in various conductive layers dueto manufacturing defects in the flexible circuit structures or wear andtear of devices employing the flexible circuit structures. Although suchconditions may arise in other contexts, they may be particularlyimportant in medical device systems where consequences of an open orotherwise impaired circuit might be associated with elevated risk orprolonged procedure times. For example, in procedures configured totreat atrial fibrillation, various transducers are employed toselectively deliver RF energy to various tissue structures within abodily cavity (e.g., a tissue cavity such as an intra-cardiac cavity).The energy delivered to the tissue structures may be sufficient forablating portions of the tissue structures. In various embodiments, thetissue structures are typically formed from non-fluidic tissue and theenergy sufficient for ablating portions of the tissue structures istypically referred to as sufficient for tissue ablation. It is notedthat in cases in which the transducers and associated circuitry areprovided by flexible printed circuit structures, the presence ofstress-induced or otherwise formed or induced open or otherwise impairedcircuits in the flexible printed circuit structures may adversely impactthe ability to deliver the energy required for tissue ablation. Itshould be noted that cracks or other breakages in a flexible circuitstructure may cause open or otherwise impaired circuits to occur in anyone or more of an electrode-based circuit, a resistive element-basedcircuit, a voltage-based or current-based measurement circuit, or anyother part of a transducer-based circuit.

Various example embodiments described herein provide robust andredundant circuit features that permit continued operation of all orsome portions of the flexible circuit structure when some portions ofthe flexible circuit structure are rendered open or impaired due tocracks or other breakages. Various example embodiments described hereinprovide robust flexible circuit features with enhanced resistance tocracks or other breakages.

In some embodiments, various transducers may include electrodes orresistive elements to detect, sense, or measure various conditions. Theelectrodes may also be configured to deliver energy to affect thesurroundings, such as bodily tissue, in some embodiments. For example,various transducers produced by flexible printed circuit structures maybe provided to measure properties such as a temperature of tissue areasproximate the various transducers. In some embodiments, elements of suchtransducers may be formed using resistive circuit elements providing afunction of detecting temperature. These resistive elements may betermed resistance temperature detectors according to some embodiments.The resistive elements may be connected in a chain such that a currentflowing through each resistive element is substantially the same. Insome embodiments, additional circuits, such as voltage or currentmeasurement circuits, may connect to the resistive elements to measurevoltage across each resistive element and electric current that flowsthrough the chain of resistive elements. In some embodiments, theresistive elements may form resistance temperature detectors to measurethe temperature proximate the surrounding tissue. In some embodiments,the resistance temperature detectors may measure temperature at leastproximate the surrounding tissue to determine whether the tissue isfluidic or non-fluidic. It should be noted that some embodiments do notrequire direct contact between at least part of the transducer and thesurrounding tissue for measurement of various properties such as thetemperature of the surrounding tissue. In some embodiments, theresistance temperature detectors may measure temperature at leastproximate the surrounding tissue to determine whether an associatedtransducer is, or is not, in contact with a particular neighboringtissue.

Various arrangements of transducer elements electrically connectedtogether in a chain-like fashion are described in commonly assigned U.S.Pat. No. 8,906,011, issued Dec. 9, 2014. These various chain-likearrangements reduce the number of leads required to measure variousproperties such as temperature with the transducer elements, therebyreducing the real estate requirements of the transducers and the leadsand thereby allowing the use of several hundreds of transducers withinthe spatial constraints imposed by most catheter-based procedures. Thedescribed transducers elements are made from a material that has areadily detectable change in the resistance with temperature. Changes intemperature correlate with changes in resistance, and the resistance maybe determined by measuring the voltage across the transducer element(resistance temperature detector—RTD) for a given current, oralternatively, by measuring the current flowing through the transducerelement for a given voltage applied across the transducer element (e.g.,via a Wheatstone bridge circuit). FIG. 14 is a conventional chain-likearrangement of resistive transducer elements 1420 a, 1420 b and 1420 c(collectively, resistive transducer elements 1420) arranged proximatenon-fluidic tissue 1400. To determine temperature by measuring theresistance of transducer element 1420 b, the voltage at lead 1422 a andlead 1422 b should be made equal and the voltage at a lead 1422 c andlead 1422 d should be made equal, but to a different voltage than thatof lead 1422 a and lead 1422 b (leads 1422 a, 1422 b, 1422 c and 1422 dcollectively referred to as leads 1422). In this condition, a small(possibly negligible) current may flow through transducer element 1420 aand transducer element 1420 c. Therefore, the current flowing throughlead 1422 b and lead 1422 c is essentially the same as the currentflowing through the transducer element 1420 b, and the resistance of thetransducer element 1420 b may be calculated in a straightforward mannerusing the equation V=I*R, known in the art. It is noted that theresistance of an electrically conductive metal (e.g., copper) changesbased on the temperature of the electrically conductive metal asdescribed later in this disclosure. Accordingly, temperature changes andtemperatures may be determined based upon the measured resistance. It isnoted that adjacent transducer elements 1420 sharing common leads 1422may, e.g., be used in a one-dimensional line of connected transducerelements 1420 or may be used in two-dimensional or three-dimensionalarrays of connected transducer elements 1420.

FIG. 15 is a plan view of a portion of a flexible circuit structure 1500that includes a plurality of conductive flexible circuit layersinterleaved with a plurality of nonconductive flexible circuit layersaccording to various flexible circuit manufacturing techniques. It isnoted in FIG. 15 that only two conductive flexible circuit layers 1504 aand 1504 b are called out and are tangentially indicated by variousrespective elements that are patterned in them. In the plan view of FIG.15, it is to be understood that the respective elements formed in theconductive flexible circuit layer 1504 b are overlapped by at least onenonconductive circuit layer (not shown in FIG. 15) and by at least theconductive flexible layer 1504 a. A plurality of resistive elements 1509(three called out by reference symbols 1509 a, 1509 b and 1509 c in FIG.15) are patterned in conductive flexible circuit layer 1504 b. In thisparticular case, the resistive elements 1509 are resistance temperaturedetectors. The resistive elements 1509 are electrically connected inseries by a plurality of conductive elements 1520 that are patterned inconductive flexible circuit layer 1504 b. A group of voltagemeasurements leads 1510 patterned in conductive flexible circuit layer1504 b are electrically connected to the resistive elements 1509 tomeasure voltage across each of resistive elements 1509 (e.g., in amanner similar to that described with respect to FIG. 14). A pluralityof electrodes 1515 are patterned in conductive flexible circuit layer1504 a, each electrode 1515 overlapping at least a respective one of theresistive elements 1509 as viewed in the plan view of FIG. 15. It isnoted that each conductive element 1520 is wider than the correspondingadjacent resistive element 1509 to reduce the resistance of theconnection between the corresponding adjacent resistive elements 1509.The transition in width from the conductive element 1520 to the adjacentresistive element 1509 can cause stress concentrations that can lead tocracks in the conductive element 1520 itself or in a connection betweenthe conductive element 1520 and adjacent resistive element 1509 when theflexible circuit structure 1500 is moved (e.g., flexed). Cracks canoccur in the conductive element 1520 itself, or in a connection areabetween the conductive element 1520 and adjacent resistive element 1509in regions near the edges of the electrodes 1515 because the electrodes1515 are relatively stiffer than other conductive components (e.g., theelectrodes 1515 typically include a relatively large electricallyconductive surface region which provides relatively higher stiffness).These cracks may ultimately lead to open circuits. It is noted that ifan open circuit condition develops (e.g., by a stress-induced failure inthe connecting circuitry) in the chain of resistive elements 1509, theability of all the resistive elements 1509 to detect respectivetemperatures may be adversely impacted. If an open circuit occurs in oneof the voltage measurement leads 1510 or conductive element 1520, theability of at least some of the resistive elements 1509 to detectrespective temperatures may be adversely impacted.

In this regard, some embodiments of the present invention facilitatemultiplicity, redundancy, and failure tolerance in the circuit so thatat least some of these unintended or undesired circumstances can beavoided. However, it can be seen that various embodiments need not belimited to intra-body medical devices or even medical devices moregenerally and, instead, have broader applicability.

In this regard, in the descriptions herein, certain specific details areset forth in order to provide a thorough understanding of variousembodiments of the invention. However, one skilled in the art willunderstand that the invention may be practiced at a more general levelwithout one or more of these details. In other instances, well-knownstructures have not been shown or described in detail to avoidunnecessarily obscuring descriptions of various embodiments of theinvention.

Any reference throughout this specification to “one embodiment” or “anembodiment” or “an example embodiment” or “an illustrated embodiment” or“a particular embodiment” and the like means that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment. Thus, any appearance of thephrase “in one embodiment” or “in an embodiment” or “in an exampleembodiment” or “in this illustrated embodiment” or “in this particularembodiment” or the like in this specification is not necessarily allreferring to one embodiment or a same embodiment. Furthermore, theparticular features, structures or characteristics of differentembodiments may be combined in any suitable manner to form one or moreother embodiments.

Unless otherwise explicitly noted or required by context, the word “or”is used in this disclosure in a non-exclusive sense. In addition, unlessotherwise explicitly noted or required by context, the word “set” isintended to mean one or more, and the word “subset” is intended to meana set having the same or fewer elements of those present in the subset'sparent or superset.

Further, the phrase “at least” is or may be used herein at times merelyto emphasize the possibility that other elements may exist besides thoseexplicitly listed. However, unless otherwise explicitly noted (such asby the use of the term “only”) or required by context, non-usage hereinof the phrase “at least” nonetheless includes the possibility that otherelements may exist besides those explicitly listed. For example, thephrase, ‘based at least on A’ includes A as well as the possibility ofone or more other additional elements besides A. In the same manner, thephrase, ‘based on A’ includes A, as well as the possibility of one ormore other additional elements besides A. However, the phrase, ‘basedonly on A’ includes only A. Similarly, the phrase ‘configured at leastto A’ includes a configuration to perform A, as well as the possibilityof one or more other additional actions besides A. In the same manner,the phrase ‘configured to A’ includes a configuration to perform A, aswell as the possibility of one or more other additional actions besidesA. However, the phrase, ‘configured only to A’ means a configuration toperform only A.

The word “device”, the word “machine”, and the phrase “device system”all are intended to include one or more physical devices or sub-devices(e.g., pieces of equipment) that interact to perform one or morefunctions, regardless of whether such devices or sub-devices are locatedwithin a same housing or different housings. However, it may beexplicitly specified that a device or machine or device system resideentirely within a same housing to exclude embodiments where therespective device, machine, or device system reside across differenthousings. The word “device” may equivalently be referred to as a “devicesystem”.

Further, the phrase “in response to” may be used in this disclosure. Forexample, this phrase might be used in the following context, where anevent A occurs in response to the occurrence of an event B. In thisregard, such phrase includes, for example, that at least the occurrenceof the event B causes or triggers the event A.

In some embodiments, the term “adjacent”, the term “proximate”, or thelike refers at least to a sufficient closeness between the objectsdefined as adjacent, proximate, or the like, to allow the objects tointeract in a designated way. For example, if object A performs anaction on an adjacent or proximate object B, objects A and B would haveat least a sufficient closeness to allow object A to perform the actionon object B. In this regard, some actions may require contact betweenthe associated objects, such that if object A performs such an action onan adjacent or proximate object B, objects A and B would be in contact,for example, in some instances or embodiments where object A needs to bein contact with object B to successfully perform the action. In someembodiments, the term “adjacent”, the term “proximate”, or the likeadditionally or alternatively refers to objects that do not have anothersubstantially similar object between them. For example, object A andobject B could be considered adjacent or proximate if they contact eachother (and, thus, it could be considered that no other object is betweenthem), or if they do not contact each other but no other object that issubstantially similar to object A, object B, or both objects A and B,depending on the embodiment, is between them. In some embodiments, theterm “adjacent”, the term “proximate”, or the like additionally oralternatively refers to at least a sufficient closeness between theobjects defined as adjacent, proximate, or the like, the sufficientcloseness being within a range that does not place any one or more ofthe objects into a different or dissimilar region, or does not change anintended function of any one or more of the objects or of anencompassing object that includes a set of the objects. Differentembodiments of the present invention adopt different ones orcombinations of the above definitions. Of course, however, the term“adjacent”, the term “proximate”, or the like is not limited to any ofthe above example definitions, according to some embodiments. Inaddition, the term “adjacent” and the term “proximate” do not have thesame definition, according to some embodiments.

The word “fluid” as used in this disclosure should be understood toinclude any fluid that can be contained within a bodily cavity or canflow into or out of, or both into and out of a bodily cavity via one ormore bodily openings positioned in fluid communication with the bodilycavity. In some embodiments, the word “fluid” may include fluid that isnot inherent to the bodily cavity, such as saline or other fluid thatmight artificially introduced into the bodily cavity. In the case ofcardiac applications, fluid such as blood will flow into and out ofvarious intra-cardiac cavities (e.g., a left atrium or right atrium).

The phrase “bodily opening” as used in this disclosure should beunderstood to include a naturally occurring bodily opening or channel orlumen; a bodily opening or channel or lumen formed by an instrument ortool using techniques that may include, but are not limited to,mechanical, thermal, electrical, chemical, and exposure or illuminationtechniques; a bodily opening or channel or lumen formed by trauma to abody; or various combinations of one or more of the above or otherbodily openings. Various elements including respective openings, lumensor channels and positioned within the bodily opening (e.g., a cathetersheath) may be present in various embodiments. These elements mayprovide a passageway through a bodily opening for various devicesemployed in various embodiments.

The words “bodily cavity” as used in this disclosure should beunderstood to mean a cavity in a body. The bodily cavity may be a cavityprovided in a bodily organ (e.g., an intra-cardiac cavity or chamber ofa heart).

The word “tissue” as used in this disclosure may include non-fluidictissue and fluidic tissue. Non-fluidic tissue generally (orpredominantly) has solid-like properties, such as tissue that forms asurface of a body or a surface within a bodily cavity, a surface of ananatomical feature or a surface of a feature associated with a bodilyopening positioned in fluid communication with the bodily cavity.Non-fluidic tissue can include part or all of a tissue wall or membranethat defines a surface of the bodily cavity. In this regard, the tissuecan form an interior surface of the cavity that at least partiallysurrounds a fluid within the cavity. In the case of cardiacapplications, non-fluidic tissue can include tissue used to form aninterior surface of an intra-cardiac cavity such as a left atrium orright atrium. Fluidic tissue, on the other hand, generally (orpredominantly) has fluid-like properties (as compared to solid-likeproperties). An example of fluidic tissue is blood. In this regard, itshould be noted that fluidic tissue can have some solid-likecomponent(s) (e.g., fluidic tissue may include solid-like components),and non-fluidic tissue can have some fluid-like component(s) (e.g.,non-fluidic tissue may include fluidic tissue within it). Unlessotherwise explicitly noted or required by context, the word “tissue”should include non-fluidic tissue and fluidic tissue. However, somecontexts where the word “tissue” would not include fluidic tissue arewhen tissue ablation is discussed, and ablation of fluidic tissue couldbe undesired. In various embodiments, non-fluidic tissue does notinclude excised tissue.

The word “ablation” as used in this disclosure should be understood toinclude any disruption to certain properties of tissue. Most commonly,the disruption is to the electrical conductivity of tissue and may beachieved by heating, which may be generated with resistive orradio-frequency (RF) techniques for example. Other properties of tissue,such as mechanical or chemical, and other means of disruption, such asoptical and electroporation are included when the term “ablation” isused. In some embodiments, ablative power levels may be within the rangeof 3 W to 5 W (as compared, e.g., to a non-tissue-ablative power levelrange of 50 m W to 60 mW that may be used for typical impedancedeterminations). In some embodiments, ratios of employed ablative powerlevels to employed non-tissue-ablative power levels (e.g., used fortypical impedance determinations) may be: at least equal or greater than50:1 in various embodiments; at least greater than 60:1 in someembodiments; at least greater than 80:1 in other various embodiments;and at least greater than 100:1 in yet other embodiments. In someembodiments, systems are configured to perform ablation of non-fluidictissue while avoiding the delivery of excessive energy to fluidictissue, because energy that is sufficient to ablate non-fluidic tissuemay also impact fluidic tissue in some circumstances. For example,energy that is sufficient to ablate non-fluidic tissue, in somecircumstances, may cause blood (an example of fluidic tissue) tocoagulate. In these and other embodiments where ablative energytransferred to fluidic tissue is not desired, it should be understoodthat any statement or reference to the ‘ablation of tissue’ or the likein these contexts is intended to refer to ablation of non-fluidictissue, as opposed to ablation of fluidic tissue. Techniques, accordingto some embodiments disclosed herein, facilitate the detection ofconditions where energy that is intended to ablate non-fluidic tissuemight unintentionally be delivered to fluidic tissue (e.g., blood) oranother object.

The term “transducer” as used in this disclosure should be interpretedbroadly as any device capable at least of distinguishing between fluidand non-fluidic tissue, sensing temperature, creating heat, ablatingtissue, and measuring electrical activity of a tissue surface,stimulating tissue or any combination thereof. A transducer can convertinput energy of one form into output energy of another form. Withoutlimitation, a transducer may include an electrode, and references to a“transducer” herein may be replaced with “electrode” according to someembodiments. Without limitation, a transducer may include a resistiveelement, and references to a “transducer” herein may be replaced with“resistive element” according to some embodiments. Without limitation, atransducer may include an electrode, a resistive element, or a sensingdevice, or a combination of any two or all of an electrode, a resistiveelement, and a sensing device. An electrode or a resistive element, insome embodiments, may be configured at least as a sensing device.Because a transducer may include an electrode according to variousembodiments, any reference herein to a transducer may also imply areference to an electrode, or vice versa. A transducer may beconstructed from several parts, which may be discrete components or maybe integrally formed.

The term “activation” should be interpreted broadly as making active aparticular function as related to various transducers such as thosedisclosed herein, for example. Particular functions may include, but arenot limited to, tissue ablation, sensing electrophysiological activity,sensing temperature and sensing electrical characteristics (e.g., tissueimpedance). For example, in some embodiments, activation of a tissueablation function of a particular transducer is initiated by causingenergy sufficient for tissue ablation to be delivered to the particulartransducer from an energy source device system. In some embodiments,activation of a tissue ablation function of a particular electrode isinitiated by causing energy from an energy source device system to bedelivered to the particular electrode, the energy sufficient for tissueablation. In some embodiments, activation of a tissue ablation functionof a particular electrode is initiated by causing energy sufficient fortissue ablation to be transmitted by the particular electrode.Alternatively, in some embodiments, the activation may be deemed to beinitiated when the particular transducer or particular electrode causestissue that is to be ablated to reach or acquire a temperaturesufficient for ablation of the tissue, which may be due to the energyprovided by the energy source device system or due to the energytransmitted by the particular transducer or electrode. In someembodiments, the activation may last for a duration concluding when theablation function is no longer active, such as when energy sufficientfor the tissue ablation is no longer provided to, or transmitted by, theparticular transducer or particular electrode. Alternatively, in someembodiments, the activation period may be deemed to be concluded whenthe tissue that is being ablated has a temperature below that sufficientfor ablation of the tissue, which may be due to a reduction or cessationof the energy provided by the energy source device system or transmittedby the particular transducer or electrode. In some contexts, however,the word “activation” may merely refer to the initiation of theactivating of a particular function, as opposed to referring to both theinitiation of the activating of the particular function and thesubsequent duration in which the particular function is active. In thesecontexts, the phrase or a phrase similar to “activation initiation” maybe used. For example, in some embodiments, activation initiation maycause initiation of a transmission of energy (e.g., energy sufficientfor tissue ablation) from a particular transducer or electrode.

The term “program” in this disclosure should be interpreted as a set ofinstructions or modules that can be executed by one or more componentsin a system, such as a controller system or data processing devicesystem, in order to cause the system to perform one or more operations.The set of instructions or modules may be stored by any kind of memorydevice, such as those described subsequently with respect to the memorydevice system 130 shown in FIG. 1. In addition, it may be described thatthe instructions or modules of a program are configured to cause theperformance of a function. The phrase “configured to” in this context isintended to include at least (a) instructions or modules that arepresently in a form executable by one or more data processing devices tocause performance of the function (e.g., in the case where theinstructions or modules are in a compiled and unencrypted form ready forexecution), and (b) instructions or modules that are presently in a formnot executable by the one or more data processing devices, but could betranslated into the form executable by the one or more data processingdevices to cause performance of the function (e.g., in the case wherethe instructions or modules are encrypted in a non-executable manner,but through performance of a decryption process, would be translatedinto a form ready for execution). The word “module” may be defined as aset of instructions.

Further, it is understood that information or data may be operated upon,manipulated, or converted into different forms as it moves throughvarious devices or workflows. In this regard, unless otherwiseexplicitly noted or required by context, it is intended that anyreference herein to information or data includes modifications to thatinformation or data. For example, “data X” may be encrypted fortransmission, and a reference to “data X” is intended to include bothits encrypted and unencrypted forms. For another example, “imageinformation Y” may undergo a noise filtering process, and a reference to“image information Y” is intended to include both the pre-processed formand the noise-filtered form. In other words, both the pre-processed formand the noise-filtered form are considered to be “image information Y”.In order to stress this point, the phrase “or a derivative thereof” orthe like may be used herein. Continuing the preceding example, thephrase “image information Y or a derivative thereof” refers to both thepre-processed form and the noise-filtered form of “image information Y”,with the noise-filtered form potentially being considered a derivativeof “image information Y”. However, non-usage of the phrase “or aderivative thereof” or the like nonetheless includes derivatives ormodifications of information or data just as usage of such a phrasedoes, as such a phrase, when used, is merely used for emphasis.

FIG. 1 schematically illustrates a system 100 according to someembodiments. In some embodiments, the system 100 may include a medicaldevice system. System 100 is not limited to medical device systems, andmay be another type of system, such as a system configured to deliverenergy (e.g., tissue-ablative energy or energy sufficient to sensetemperature or an electrical characteristic) to one or more resistiveelements in a flexible printed circuit structure. In this regard, system100 may include sensing or operative circuits where energy in the formof electric current is transmitted through the circuit(s) to measure orcontrol various properties of connected components or the surroundingenvironment.

In some embodiments, the medical device system 100 includes a dataprocessing device system 110, an input-output device system 120, and aprocessor-accessible memory device system 130. The processor-accessiblememory device system 130 and the input-output device system 120 arecommunicatively connected to the data processing device system 110.

The data processing device system 110 includes one or more dataprocessing devices that implement or execute, in conjunction with otherdevices, such as one or more of those in the system 100, one or morecontrol programs associated with some of the various embodiments. Eachof the phrases “data processing device”, “data processor”, “processor”,and “computer” is intended to include any data processing device, suchas a central processing unit (“CPU”), a desktop computer, a laptopcomputer, a mainframe computer, a tablet computer, a personal digitalassistant, a cellular phone, and any other device configured to processdata, manage data, or handle data, whether implemented with electrical,magnetic, optical, biological components, or other.

The memory device system 130 includes one or more processor-accessiblememory devices configured to store information, including theinformation needed to execute the control programs associated with atleast some of the various embodiments. The memory device system 130 maybe a distributed processor-accessible memory device system includingmultiple processor-accessible memory devices communicatively connectedto the data processing device system 110 via a plurality of computersand/or devices. On the other hand, the memory device system 130 need notbe a distributed processor-accessible memory device system and,consequently, may include one or more processor-accessible memorydevices located within a single data processing device.

Each of the phrases “processor-accessible memory” and“processor-accessible memory device” is intended to include anyprocessor-accessible data storage device, whether volatile ornonvolatile, electronic, magnetic, optical, or otherwise, including butnot limited to, registers, floppy disks, hard disks, Compact Discs,DVDs, flash memories, ROMs, and RAMs. In some embodiments, each of thephrases “processor-accessible memory” and “processor-accessible memorydevice” is intended to include a non-transitory computer-readablestorage medium. In some embodiments, the memory device system 130 may beconsidered a non-transitory computer-readable storage medium system.

The phrase “communicatively connected” is intended to include any typeof connection, whether wired or wireless, between devices, dataprocessors, or programs in which data may be communicated. Further, thephrase “communicatively connected” is intended to include a connectionbetween devices or programs within a single data processor, a connectionbetween devices or programs located in different data processors, and aconnection between devices not located in data processors at all. Inthis regard, although the memory device system 130 is shown separatelyfrom the data processing device system 110 and the input-output devicesystem 120, one skilled in the art will appreciate that the memorydevice system 130 may be located completely or partially within the dataprocessing device system 110 or the input-output device system 120.Further in this regard, although the input-output device system 120 isshown separately from the data processing device system 110 and thememory device system 130, one skilled in the art will appreciate thatsuch system may be located completely or partially within the dataprocessing system 110 or the memory device system 130, depending uponthe contents of the input-output device system 120. Further still, thedata processing device system 110, the input-output device system 120,and the memory device system 130 may be located entirely within the samedevice or housing or may be separately located, but communicativelyconnected, among different devices or housings. In the case where thedata processing device system 110, the input-output device system 120,and the memory device system 130 are located within the same device, thesystem 100 of FIG. 1 may be implemented by a single application specificintegrated circuit (ASIC) in some embodiments.

The input-output device system 120 may include a mouse, a keyboard, atouch screen, another computer, or any device or combination of devicesfrom which a desired selection, desired information, instructions, orany other data is input to the data processing device system 110. Theinput-output device system 120 may include a user-activatable controlsystem that is responsive to a user action, such as actions from a careprovider such as a physician or technician. The input-output devicesystem 120 may include any suitable interface for receiving information,instructions or any data from other devices and systems described invarious ones of the embodiments. In this regard, the input-output devicesystem 120 may include various ones of other systems described invarious embodiments. For example, the input-output device system 120 mayinclude at least a portion of a transducer-based device system or anelectrode-based device system. The phrase “transducer-based devicesystem” is intended to include one or more physical devices or systemsthat include various transducers. Similarly, the phrase “electrode-baseddevice system” is intended to include one or more physical devices orsystems that include various electrodes. In this regard, the phrases“transducer-based device system” and “electrode-based device system” maybe used interchangeably in accordance with various embodiments.Similarly, the phrases “transducer-based device” and “electrode-baseddevice” may be used interchangeably in accordance with variousembodiments. In this regard, the phrases “transducer-based devicesystem” and “electrode-based device system” may be used interchangeablywith “resistive-element-based device system” in accordance with variousembodiments. Similarly, the phrases “transducer-based device” and“electrode-based device” may be used interchangeably with “resistiveelement-based device” in accordance with various embodiments.

The input-output device system 120 also may include an image generatingdevice system, a display device system, a speaker device system, aprocessor-accessible memory device system, or any device or combinationof devices to which information, instructions, or any other data isoutput from the data processing device system 110. In this regard, ifthe input-output device system 120 includes a processor-accessiblememory device, such memory device may or may not form part or all of thememory device system 130. The input-output device system 120 may includeany suitable interface for outputting information, instructions or datato other devices and systems described in various ones of theembodiments. In this regard, the input-output device system may includevarious other devices or systems described in various embodiments.

FIG. 2 shows a transducer-based device system 200, which may be includedin the input-output device system 120 of FIG. 1, according to someembodiments. Because, as described in more detail below with respect toFIG. 4, electrodes or resistive elements may be part of transducers,according to some embodiments, the system 200 may also be considered anelectrode-based device system or a resistive element-based device systemin some embodiments. Such a system 200 may be useful for, among otherthings, investigating or treating a bodily organ, for example a heart202, according to some example embodiments. The transducer-based devicesystem 200 can be percutaneously or intravascularly inserted into aportion of the heart 202, such as an intra-cardiac cavity like leftatrium 204. In this example, the transducer-based device system 200includes a catheter 206 inserted via the inferior vena cava 208 andpenetrating through a bodily opening in transatrial septum 210 fromright atrium 212. In other embodiments, other paths may be taken.

Catheter 206 may include an elongated flexible rod or shaft memberappropriately sized to be delivered percutaneously or intravascularly.Various portions of catheter 206 may be steerable. Catheter 206 mayinclude one or more lumens. The lumen(s) may carry one or morecommunications or power paths, or both. For example, the lumens(s) maycarry one or more electrical conductors 216 (two shown in thisembodiment). Electrical conductors 216 provide electrical connectionsfor system 200 that are accessible externally from a patient in whichthe transducer-based device system 200 is inserted.

In some embodiments, the electrical conductors 216 may provideelectrical connections to transducers 220 (three called out in FIG. 2)that respectively include one or more electrodes, and optionally one ormore other devices, (e.g., both discussed with respect to FIG. 4, below)configured to, among other things, provide stimulation (e.g., electricalstimulation that may include pinging or pacing) to tissue within abodily cavity (e.g., left atrium 204), ablate tissue in a desiredpattern within the bodily cavity, sense characteristics of tissue (e.g.,electrophysiological activity, convective cooling, permittivity, force,temperature, impedance, thickness, or a combination thereof) within thebodily cavity, or a combination thereof. In some embodiments, therespective portions of transducers 220 may be connected in seriesthrough conductive elements (not shown in FIG. 2 but discussed withrespect to FIG. 4, below) that facilitate multiplicity, redundancy, andfailure tolerance in associated circuits of system 200.

The sensing of characteristics may, among other things, be configured todistinguish between fluid, such as fluidic tissue (e.g., blood), andnon-fluidic tissue forming an interior surface of a bodily cavity (e.g.,left atrium 204), may be configured to map the cavity, for example,using positions of openings or ports into and out of the cavity todetermine a position or orientation (e.g., pose), or both of a portionof the device system 200 in the bodily cavity, may be configured toindicate whether an ablation has been successful; or a combinationthereof.

Transducer-based device system 200 may include a frame or structure 218which assumes an unexpanded or delivery configuration (e.g., FIG. 3A,discussed below) for delivery to left atrium 204. Structure 218 isdeployable or expandable (i.e., shown in a deployed or expandedconfiguration in FIG. 2,) upon delivery to left atrium 204. Anotherembodiment of a deployed or expanded configuration is also shown in FIG.3B, which is discussed below. In this regard, in some embodiments, thetransducer-based device system 200 is moveable between a delivery orunexpanded configuration (e.g., similar to FIG. 3A, discussed below) inwhich a portion (e.g., the structure 218) of the device system 200 issized for passage through a bodily opening leading to a bodily cavity,and a deployed or expanded configuration (e.g., FIG. 2,) in which theportion of the device system 200 has a size too large for passagethrough the bodily opening leading to the bodily cavity. An example ofan expanded or deployed configuration is when the portion of thetransducer-based device system is in its intended-deployed-operationalstate inside the bodily cavity. Another example of the expanded ordeployed configuration is when the portion of the transducer-baseddevice system is being changed from the delivery configuration to theintended-deployed-operational state to a point where the portion of thedevice system now has a size too large for passage through the bodilyopening leading to the bodily cavity. Further, in some embodiments, whenthe portion (e.g., the structure 218) is in the expanded or deployedconfiguration in the left atrium 204, various ones of a plurality oftransducers 220 are positioned proximate the interior surface formed bynon-fluidic tissue 222 of left atrium 204. In some embodiments, when theportion (e.g., the structure 218) is in the expanded or deployedconfiguration in the left atrium 204, various ones of a plurality oftransducers 220 are positioned such that a physical portion of each ofthe various ones of the transducers 220 is configured to contact theinterior surface formed by non-fluidic tissue 222 of left atrium 204. Insome embodiments, at least some of the transducers 220 are configured tosense a physical characteristic of a fluid (i.e., blood), non-fluidictissue 222 (i.e., cardiac wall tissue), or both, that may be used todetermine a position or orientation (i.e., pose), or both, of a portionof a device system 200 within, or with respect to left atrium 204. Forexample, transducers 220 may be configured to determine a location ofpulmonary vein ostia or a mitral valve 226, or both. In someembodiments, at least some of the transducers 220 may be controlled toselectively ablate portions of the non-fluidic tissue 222. For example,some of the transducers 220 may be controlled to ablate a pattern orpath around various ones of the bodily openings, ports or pulmonary veinostia, for instance, to reduce or eliminate the occurrence of atrialfibrillation. Each of various ones of the transducers 220 may include anelectrode in various embodiments, as described below with respect toFIG. 4, for example. Each of various ones of the transducers 220 mayinclude resistive element in various embodiments, as described belowwith respect to FIG. 4, for example.

Each of FIGS. 3A and 3B is a partially schematic representation of amedical device system, which may represent one or more implementationsof the medical device system 100 of FIG. 1, according to someembodiments. In this regard, the medical device system in each of FIGS.3A and 3B may be configured to deliver energy to one or more resistiveelements, such as a transducer or electrode. Each of the medical devicesystems of FIGS. 3A and 3B includes a transducer-based device system300. The transducer-based device system 300 may include several hundredsof electrodes 315, but need not include that many. FIG. 3A illustratesthe transducer-based device system 300 in the delivery or unexpandedconfiguration, according to various example embodiments, and FIG. 3Billustrates the transducer-based device system 300 in the deployed orexpanded configuration, according to some embodiments.

In this regard, the transducer-based device system 300 includes aplurality of elongate members 304 (three called out in each of FIGS. 3Aand 3B) and a plurality of transducers 306 (three called out in FIG. 3Aand three called out in FIG. 3B as 306 a, 306 b and 306 c). In someembodiments, the transducers 306 have the configuration of thetransducers 220 in FIG. 2. In some embodiments, the transducers 306 areformed as part of, or are located on, the elongate members 304. In someembodiments, the elongate members 304 are arranged as a frame orstructure 308 that is selectively movable between an unexpanded ordelivery configuration (e.g., as shown in FIG. 3A) and an expanded ordeployed configuration (e.g., as shown in FIG. 3B) that may be used toposition elongate members 304 or various one of the transducers 306against a tissue surface within the bodily cavity or position theelongate members 304 in the vicinity of, or in contact with, the tissuesurface.

In some embodiments, the structure 308 has a size in the unexpanded ordelivery configuration suitable for percutaneous delivery through abodily opening (e.g., via catheter sheath 312, not shown in FIG. 3B) tothe bodily cavity. In some embodiments, structure 308 has a size in theexpanded or deployed configuration too large for percutaneous deliverythrough a bodily opening (e.g., via catheter sheath 312) to the bodilycavity. The elongate members 304 may form part of a flexible circuitstructure (i.e., also known as a flexible printed circuit board (PCB)).The elongate members 304 may include a plurality of different materiallayers, and each of the elongate members 304 may include a plurality ofdifferent material layers. The structure 308 may include a shape memorymaterial, for instance Nitinol. The structure 308 may include a metallicmaterial, for instance stainless steel, or non-metallic material, forinstance polyimide, or both a metallic and non-metallic material by wayof non-limiting example. The incorporation of a specific material intostructure 308 may be motivated by various factors including the specificrequirements of each of the unexpanded or delivery configuration andexpanded or deployed configuration, the required position or orientation(i.e., pose) or both of structure 308 in the bodily cavity, or therequirements for successful ablation of a desired pattern.

The plurality of transducers 306 are positionable within a bodilycavity, for example, by positioning of the structure 308. For instance,in some embodiments, the transducers 306 are able to be positioned in abodily cavity by movement into, within, or into and within the bodilycavity, with or without a change in a configuration of the plurality oftransducers 306 (e.g., a change in a configuration of the structure 308causes a change in a configuration of the transducers 306 in someembodiments). In some embodiments, the plurality of transducers 306 arearrangeable to form a two- or three-dimensional distribution, grid orarray capable of mapping, ablating or stimulating an inside surface of abodily cavity or lumen without requiring mechanical scanning. As shown,for example, in FIG. 3A, the plurality of transducers 306 are arrangedin a distribution receivable in a bodily cavity (not shown in FIG. 3A).As shown, for example, in FIG. 3A, the plurality of transducers 306 arearranged in a distribution suitable for delivery to a bodily cavity.

FIG. 4 is a schematic representation of at least a portion of atransducer-based device system 400 that includes a flexible circuitstructure 401 that is employed to provide a plurality of transducers 406(two called out) according to various example embodiments. In someembodiments, the transducer-based device system 400 corresponds to atleast part of the transducer-based device system 300 and transducers 406correspond to the transducers 306. In some embodiments, thetransducer-based device system 400 corresponds to at least part of thetransducer-based device system 200 and transducers 406 correspond to thetransducers 220. In some embodiments, the flexible circuit structure 401may form part of a structure (e.g., structure 308) that is selectivelymovable between a delivery configuration sized for percutaneous deliveryand an expanded or deployed configuration sized too large forpercutaneous delivery. In some embodiments, the flexible circuitstructure 401 may be located on, or form at least part of, a structuralcomponent (e.g., elongate member 304) of a transducer-based devicesystem (e.g., transducer-based device system 200, 300, 400). In someembodiments, the flexible circuit structure 401 is provided on anon-expandable surface of a catheter, the non-expandable portionconfigured to not be selectively expandable between two states (e.g., adelivery configuration and a deployed configuration as exemplified inFIGS. 3A and 3B). In some embodiments, the flexible circuit structuremay be located on a surface of an elongate shaft of a catheter.

The flexible circuit structure 401 may be formed by various techniquesincluding flexible printed circuit techniques. In some embodiments, theflexible circuit structure 401 includes various conductive andnonconductive flexible layers. One or more of the nonconductive flexiblelayers 403 (three called out in FIG. 4 as reference symbols 403 a, 403 band 403 c) may form a substrate for the flexible circuit structure andmay be interleaved with one or more of the conductive layers 404 toelectrically or physically separate one or more conductive layers fromother conductive layers. In some embodiments, each of the nonconductiveflexible layers 403 includes an electrical insulator material (e.g.,polyimide). One or more of the nonconductive flexible layers 403 mayinclude a different material than another of the nonconductive flexiblelayers 403 in some embodiments. One or more of the electricallyconductive layers 404 (three called out in FIG. 4 as reference symbols404 a, 404 b and 404 c) may be patterned to form various electricallyconductive elements. For example, electrically conductive layer 404 amay be patterned to form a respective electrode 415 (e.g., electrode 415a, 415 b) included as part of each of the transducers 406. Electrodes415 may have respective electrode edges 415-1 that form a periphery ofan electrically conductive surface or surface portion associated withthe respective electrode 415.

In some embodiments, the respective electrically conductive surface orsurface portion of one or more of the electrodes 415 is configured totransmit energy to contacting tissue at a level sufficient for ablationof the tissue. Other energy levels may be transmitted to, for example,provide stimulation (e.g., electrical stimulation that may includepinging or pacing) to tissue within a bodily cavity (e.g., left atrium204), sense characteristics of tissue (e.g., electrophysiologicalactivity, convective cooling, permittivity, force, temperature,impedance, tissue thickness, or a combination thereof) within the bodilycavity, or a combination thereof.

Electrically conductive layer 404 b may be patterned, in someembodiments, to form respective temperature sensors 408 (e.g., resistivetemperature detectors) for each of the transducers 406 as well asvarious leads 410 a arranged to measure respective voltage associatedwith each of the temperature sensors 408. In some embodiments, eachtemperature sensor 408 includes an electrical load such as a patternedresistive element 409 (two called out in FIG. 4 as reference symbols 409a and 409 b) having a predetermined electrical resistance. In someembodiments, each resistive element 409 includes a metal havingrelatively high electrical conductivity (e.g., copper). In someembodiments, the resistive element 409 has a serpentine form. Theserpentine form has the advantage of providing an increase in theoverall resistance of resistive element 409 by increasing its overalllength while maintaining a compact spatial arrangement. In someembodiments, each resistive element 409 is connected to an adjacentresistive element 409 by a conductive element, such as a conductive mesh420. The conductive mesh 420 provides multiple, redundant, and failuretolerant electrical connections between adjacent pairs of resistiveelements 409, thereby increasing the robustness and durability of theflexible circuit structure 401. It should be noted that, althoughconductive meshes 420 (also referred to herein as “meshes”) are providedas examples of conductive elements that couple adjacent resistiveelements in a circuit, such conductive elements may be provided by otherstructures providing multiple, redundant, and failure tolerantelectrical connections between adjacent pairs of resistive elements 409and need not have the equal conductive segment (e.g., 430 a, 430 b, 430c) spacing illustrated, although such a spacing may be beneficial insome embodiments. Each of the electrodes 415 may overlap, or partiallyoverlap a respective resistive element 409. As discussed previously, theelectrodes 415 may be stiffer than other portions of the flexiblecircuit structure 401. This higher stiffness may increase a likelihoodof the occurrence of cracks in regions at least proximate the electrodeedge 415-1 portions. In some embodiments, the likelihood of open orotherwise impaired circuits due to cracks is reduced by the multiple,redundant, and failure tolerant connections provided by the conductivemeshes 420.

In some embodiments, electrically conductive layer 404 c may bepatterned to provide portions of various connection leads 410 b arrangedto provide an electrical communication path to electrodes 415. In someembodiments, leads 410 b are arranged to pass though vias (accounted forin FIG. 4, e.g., by the upward (with respect to the proper orientationof FIG. 4) movement of the leads 410 b) in flexible layers 403 a and 403b to connect with electrodes 415. Although FIG. 4 shows flexible layer403 c as being a bottom-most layer, some embodiments may include one ormore additional layers underneath flexible layer 403 c, for example, oneor more structural layers, such as a stainless steel or composite layer.These one or more structural layers, in some embodiments, are part ofthe flexible circuit structure 401 and may be part of, e.g., elongatemember 304. In some embodiments, the flexible circuit structure 401includes a nonconductive substrate including at least one flexiblelayer. In addition, although FIG. 4 shows only three flexible layers 403a-403 c and only three electrically conductive layers 404 a-404 c, itshould be noted that other numbers of flexible layers, other numbers ofelectrically conductive layers, or both, may be included. It should benoted that the various structures of the flexible circuit system, suchas the electrode 415, resistive element 409, or conductive mesh 420, forexample, may include different metals or conductive materials accordingto some embodiments.

In FIG. 4, three conductive meshes 420 a, 420 b and 420 c are shown. Itis understood that additional resistive elements 409 and conductivemeshes 420 may be present in various example embodiments. It is notedthat various elements such as electrodes 415, resistive elements 409 andconductive meshes 420 are schematically represented in variousorientations that are convenient for the sake of clarity in FIG. 4, andthat at least some of these orientations may be different from oneanother. It is also noted that various elements are not shown to scale.For example, according to some embodiments, while layers 403 a, 403 band 403 c may be considered to be depicted by side elevation views ofthe layers on FIG. 4, electrodes 415, resistive elements 409 andconductive meshes 420 may be considered to be depicted by perspective orplan views of the particular layers they are formed from. It isunderstood that these different orientations are provided to facilitatethe discussion of these various elements and do not impose a limitationon the spatial or structural arrangements.

In some embodiments, at least a portion of the conductive mesh 420 mayspatially overlap at least a portion of an electrode 415 or may bespatially overlapped by at least a portion of an electrode 415 (e.g.,depending on the viewing direction). In FIG. 4, at least a portion ofthe conductive mesh 420 b is arranged to overlap, or be overlapped by(e.g., depending on the viewing direction), at least a portion of theelectrode 415 a as shown by the location of the electrode edge 415-1.For example, the conductive mesh 420 may be patterned in theelectrically conductive layer 404 b and the electrode 415 a may bepatterned in the electrically conductive layer 404 a, the electricallyconductive layers 404 a and 404 b arranged in an overlappingconfiguration or arrangement. The electrode 415 a and the conductivemesh 420 b are arranged so that they share an overlapped portion. Insome embodiments, at least a respective portion of the conductive mesh420 b may spatially overlap respective portions of each of at least twoof the electrodes 415 or may be spatially overlapped by respectiveportions of each of at least two of the electrodes 415. For example, atleast a portion of conductive mesh 420 b connected to the resistiveelement 409 a is overlapped, or overlaps (e.g., depending on the viewingdirection) a respective portion of the electrode 415 a and at least aportion of the conductive mesh 420 b connected to the resistive element409 b is overlapped, or overlaps (e.g., depending on the viewingdirection) a respective portion of the electrode 415 b in FIG. 4. Thisarrangement positions the connection regions between the conductive mesh420 b and resistive elements 409 a and 409 b away from the electrodeedges 415-1 of electrodes 415 a and 415 b. During bending of theflexible circuit structure, the edges 415-1 of the relatively stifferelectrodes 415 a and 415 b can concentrate bending stresses applied toconductive mesh 420 b to create a stress riser adjacent the electrodeedge. By moving the connection regions between the conductive mesh 420 band the resistive elements 409 a, 409 b away from regions proximate theelectrode edges 415-1, any potential stress risers associated with theconnection regions are not readily combined with the stress riserassociated with the electrode edge 415-1 and thereby, occurrences ofcombined stress concentration effects that can more easily lead to theformation of stress cracks during bending or flexing may be reduced.

In some embodiments, the flexible circuit structure 401 may include atleast one electrically nonconductive flexible layer 403 (electricallynonconductive substrate), at least one electrically conductive flexiblecircuit layer 404 coupled, directly or indirectly, to the at least oneelectrically nonconductive flexible layer 403. In some embodiments, theelectrically conductive flexible circuit layer 404 may includeconductive patterns including a plurality of resistive elements 409 anda plurality of conductive meshes 420. Each conductive mesh 420 of theplurality of conductive meshes electrically connects at least arespective adjacent pair of resistive elements 409 of the plurality ofresistive elements 409 according to various embodiments. Each conductivemesh 420 of the plurality of conductive meshes directly connects atleast to each of a respective adjacent pair of resistive elements 409 ofthe plurality of resistive elements 409 according to variousembodiments.

In some embodiments, the plurality of conductive meshes 420 seriallyelectrically connects the plurality of resistive elements 409 to provideat least one electric current flow path through the plurality ofresistive elements 409. Electric current flows through each of theresistive elements 409 and each of the conductive meshes 420, alongelectrical pathways providing at least one electric current flow path,according to various embodiments. In some embodiments, the conductivemeshes 420 provide multiple electrical pathways for the electric currentto pass through all of the resistive elements 409. In this regard, thephrase “electrical pathway” refers to at least one structural elementsuch as a trace of conductive material (for example, resistive element409 or conductive segment 430 discussed in more detail below) and thephrase “electric current flow path” refers to a sequential set of one ormore electrical pathways through which electric current flows or is ableto flow in the broader circuit at any given time, according to someembodiments. For example, assume that conductive segment 430 b in FIG. 4is split in the middle (not shown in FIG. 4, such split is merely beingassumed for this example) causing an open circuit in conductive segment430 b. The split-created halves of conductive segment 430 b may each bedeemed an electrical pathway, because each half comprises a trace ofconductive material, but the split-created two halves of conductivesegment 430 b would not provide an electric current flow path betweenresistive elements 409 a and 409 b, because, in the context of thelarger circuit providing the structure of FIG. 4, electric current isnot able to flow between resistive elements 409 a and 409 b via theconductive segment 430 b, because an open circuit exists in theconductive segment 430 b in this example. On the other hand, if theconductive segment 430 b is in proper working order as shown in FIG. 4,such conductive segment 430 b may be considered an electrical pathwayand may also be considered to provide an electric current flow pathbetween resistive elements 409 a and 409 b.

In this regard, an electrical pathway may be provided by a plurality ofelectrically connected traces, such as a plurality of electricallyconnected conductive segments 430. In this regard, an electrical pathwaymay be provided by a sequential grouping of all of the conductive tracesassociated with any particular electric current flow path, or asequential grouping of some of the conductive traces associated with aparticular portion of the particular electric current flow path. In someembodiments, there may be more than one electric current flow path(e.g., between resistive elements or other circuit structures), withvarying amounts of electric current flowing through each of the electriccurrent flow paths.

It should be noted that a single conductive element (such as a singleconductive segment 430, like conductive element 430 a) having across-sectional area could be considered as providing multiple virtualelectrical pathways or electric current flow paths through theconnections between particles of conductive material that form thesingle conductive element. For this disclosure, however, it isconsidered that a single conductive element (such as a single conductiveelement 430, like conductive element 430 a) provides all or a portion ofa single electrical pathway, although the portion of the singleelectrical pathway may be included as part of other electrical pathwaysformed by connections to other conductive elements (traces of conductiveparticles). For example, each particular conductive segment 430 definesa respective, single, electrical pathway, but may also be part ofmultiple, longer, electrical pathways that include the particularconductive segment 430. Similarly, an electrical pathway may be includedin multiple, different electric current flow paths.

In some embodiments, electric current flows through each of theresistive elements 409 and each of the conductive meshes 420, which arearranged such that at least one conductive mesh 420 is located betweeneach pair of resistive elements 409 that are successively arranged inseries along the electric current flow path.

In some embodiments, the flexible circuit structure 401 is electricallyconnected to a voltage or current measurement system (e.g., provided atleast in part by (a) input-output device system 120, 320, (b) dataprocessing device system 110, 310, or both (a) and (b), such as thatdescribed with respect to FIG. 16, below, according to some embodiments)by the plurality of measurement leads 410 a. In some embodiments,respective pairs of measurement leads 410 a are arranged to sensevoltage or current across each resistive element 409. In someembodiments, at least some of the measurement leads 410 a areelectrically connected to a respective conductive mesh 420. In someembodiments, voltage measurement leads 410 a are arranged to allow for asampling of electrical voltage between each resistive element 409. Thesearrangements allow for the electrical resistance of each resistiveelement 409 to be accurately determined. The ability to accuratelydetermine the electrical resistance of each resistive element 409 may bemotivated by various reasons including determining temperature values atlocations at least proximate the resistive element 409 based at least onchanges in the resistance caused by convective cooling effects (e.g., asprovided by blood flow).

In some embodiments, electrodes 415 are employed to selectively deliverRF energy to various tissue structures within a bodily cavity (e.g., atissue cavity such as an intra-cardiac cavity). The energy delivered tothe tissue structures may be sufficient for ablating portions of thetissue structures. In various embodiments, the tissue structures aretypically formed from non-fluidic tissue and the energy sufficient forablating portions of the tissue structures is typically referred to assufficient for tissue ablation. It is noted that energy sufficient fornon-fluidic-tissue ablation may include energy levels sufficient todisrupt or alter fluidic tissue (e.g., blood) that may, for example, belocated proximate the tissue structure. In many cases, the applicationof non-fluidic-tissue-ablative energy (i.e., energy that is sufficientto ablate non-fluidic tissue) to fluidic tissue, such as blood, isundesired when the energy is sufficient to disrupt or adversely impact aproperty of the fluidic tissue. For example, the application ofnon-fluidic-tissue-ablative energy to blood may be undesired when theenergy is sufficient to cause various parts of the blood to coagulate ina process typically referred to as thermal coagulation. In this regard,some embodiments facilitate detection of conditions where an electrodeconfigured to deliver non-fluidic-tissue-ablative energy may be in aconfiguration where it is not able to properly transmit such energy. Insome embodiments, a detection of such a condition results in an errornotification being transmitted or otherwise presented to a user (e.g.,via input-output device system 120, 320) or, in some embodiments, arestricting of that electrode from transmitting at least a portion ofthe non-fluidic-tissue-ablative energy (e.g., via control of energysource device system 340 (discussed below) via controller 324).

In some embodiments, each resistive element 409 is positioned adjacent arespective one of the electrodes 415. Each resistive element 409 may ormay not be in contact with the respective one of the electrodes 415, butmay be in sufficient proximity to the respective one of the electrodes415 to interact with or be influenced by tissue in proximity to therespective one of the electrodes 415. In some embodiments, each of theresistive elements 409 is positioned in a stacked or layered array witha respective one of the electrodes 415 to form a respective one of thetransducers 406.

FIG. 4 shows an example embodiment of a conductive mesh 420 b includingconductive segments 430 (three called out in FIG. 4 as reference symbols430 a, 430 b, and 430 c). Each conductive segment 430 provides one of aplurality of electrical pathways for flow of electric current, accordingto some embodiments. Each of the plurality of electrical pathwaysprovides a portion of an electric current flow path through the seriallyconnected resistive elements 409 and conductive meshes 420. In someembodiments, the plurality of conductive segments 430 provides aplurality of electrical pathways. Although conductive mesh 420 b isshown with three conductive segments 430 in FIG. 4 (i.e., 430 a, 430 band 430 c), more or fewer number of conductive segments may be providedin various embodiments. According to various embodiments, the conductivemesh 420 b provides multiple or redundant or failure tolerant electricalpathways so that an electric current flow path through the resistiveelements 409 and conductive meshes 420 may be maintained even if one ormore of the electrical pathways (e.g., one or more of the conductivesegments 430 a, 430 b, 430 c, in some embodiments) is interrupted orbroken due to cracks or other defects. In some embodiments, respectiveones of the leads 410 a are connected to respective ones of theconductive meshes 420 at more than one connection point, providingfurther multiplicity, redundancy, and failure tolerance in the circuitand robustness in the presence of cracks or other impediments to currentflow.

In some embodiments in which the transducer-based device system 200 or300 is deployed in a bodily cavity (e.g., when the transducer-baseddevice system 200 or 300 takes the form of a catheter device systemarranged to be percutaneously or intravascularly delivered (or through anatural bodily opening) to a bodily cavity), it may be desirable toperform various mapping procedures in the bodily cavity (e.g., operatingthe transducer-based device system 200 or 300 in a mapping mode). Forexample, when the bodily cavity is an intra-cardiac cavity, a desiredmapping procedure may include mapping electrophysiological activity inthe intra-cardiac cavity. Other desired mapping procedures may includemapping of various anatomical features within a bodily cavity. Anexample of the mapping performed by devices according to variousembodiments may include locating the position of the ports of variousbodily openings positioned in fluid communication with a bodily cavity.For example, in some embodiments, it may be desired to determine thelocations of various ones of the pulmonary veins or the mitral valvethat each interrupts an interior surface of an intra-cardiac cavity suchas a left atrium.

In some example embodiments, the mapping is based at least on locatingbodily openings by differentiating between fluid and non-fluidic tissue(e.g., tissue defining a surface of a bodily cavity). There are manyways to differentiate non-fluidic tissue from a fluid such as blood orto differentiate tissue from a bodily opening in case a fluid is notpresent. Four approaches may include by way of non-limiting example,and, depending upon the particular approach(es) chosen, theconfiguration transducers 406 in FIG. 4 may be implemented accordingly:

1. The use of convective cooling of heated transducer elements by fluid.When operated in a flow sensing mode, an arrangement of slightly heatedtransducer elements that is positioned adjacent to the tissue that formsthe interior surface(s) of a bodily cavity and across the ports of thebodily cavity will be cooler at the areas which are spanning the portscarrying the flow of fluid.

2. The use of tissue impedance measurements. A set of transducerspositioned adjacently to tissue that forms the interior surface(s) of abodily cavity and across the ports of the bodily cavity can beresponsive to electrical tissue impedance. Typically, heart tissue willhave higher associated tissue impedance values than the impedance valuesassociated with blood.

3. The use of the differing change in dielectric constant as a functionof frequency between blood and tissue. A set of transducers positionedaround the tissue that forms the interior surface(s) of the atrium andacross the ports of the atrium monitors the ratio of the dielectricconstant from 1 kHz to 100 kHz. Such may be used to determine which ofthose transducers are not proximate to tissue, which is indicative ofthe locations of the ports.

4. The use of transducers that sense force (i.e., force sensors). A setof force detection transducers positioned around the tissue that formsthe interior surface(s) of a bodily cavity and across the bodilyopenings or ports of the bodily cavity may be used to determine which ofthe transducers are not engaged with the tissue, which may be indicativeof the locations of the ports.

Various ones of the above approaches may be used, at least in part, todetermine proximity of a transducer to non-fluidic tissue or to fluidictissue in some embodiments.

Various ones of the above approaches may be used, at least in part, todetermine contact between a transducer and non-fluidic tissue or contactbetween a transducer and fluidic tissue in some embodiments. Variousones of the above approaches may be used, at least in part, to determinean amount of an electrically conductive surface portion of an electrodethat contacts non-fluidic tissue or contacts fluidic tissue in someembodiments. Various ones of the above approaches may be used, at leastin part, to determine an amount of an electrically conductive surfaceportion of an electrode that is available to contact non-fluidic tissueor available to contact fluidic tissue in some embodiments.

Referring again to the medical device systems of FIGS. 3A and 3B,according to some embodiments, transducer-based device system 300communicates with, receives power from or is controlled by atransducer-activation system 322, which may include a controller 324 andan energy source device system 340. In some embodiments, the controller324 includes a data processing device system 310 and a memory devicesystem 330 that stores data and instructions that are executable by thedata processing device system 310 to process information received fromother components of the medical device system of FIGS. 3A and 3B or tocontrol operation of components of the medical device system of FIGS. 3Aand 3B, for example by activating various selected transducers 306 toablate tissue, sense tissue characteristics, et cetera. In this regard,the data processing device system 310 may correspond to at least part ofthe data processing device system 110 in FIG. 1, according to someembodiments, and the memory device system 330 may correspond to at leastpart of the memory device system 130 in FIG. 1, according to someembodiments. The energy source device system 340, in some embodiments,is part of an input-output device system 320, which may correspond to atleast part of the input-output device system 120 in FIG. 1. Althoughonly a single controller 324 is illustrated, it should be noted thatsuch controller 324 may be implemented by a plurality of controllers. Insome embodiments, the transducer-based device system 300 (or 200 in FIG.2) is considered to be part of the input-output device system 320. Theinput-output device system 320 may also include a display device system332, a speaker device system 334, or any other device such as thosedescribed above with respect to the input-output device system 120.

In some embodiments, elongate members 304 may form a portion or anextension of control leads 317 that reside, at least in part, in anelongated cable 316 and, at least in part, in a flexible catheter body314. The control leads terminate at a connector 321 or other interfacewith the transducer-activation system 322 and provide communicationpathways between at least the transducers 306 and the controller 324.The control leads 317 may correspond to electrical conductors 216 insome embodiments.

As discussed with respect to FIG. 4, each of various ones of thetransducers 306, 406 includes an electrode 315, 415, according to someembodiments. In these various embodiments, each of at least some of theelectrodes 315, 415 may include a respective energy transmission surface(e.g., energy transmission surface 319 in FIG. 3A) configured totransfer, transmit, or deliver energy, for example, to tissue. In someembodiments, at least some of the respective energy transmissionsurfaces are configured to receive energy, for example, from tissue.Each of the energy transmission surfaces may be bounded by a respectiveelectrode edge 415-1 (e.g., FIG. 4).

In some embodiments, input-output device system 320 may include asensing device system 325 configured to detect various characteristicsor conditions including, but not limited to, at least one of tissuecharacteristics (e.g., electrical characteristics such as tissueimpedance, tissue type, tissue thickness) and thermal characteristicssuch as temperature. Various other particular conditions described laterin this disclosure may be detected by sensing device system 325according to various embodiments. It is noted that in some embodiments,sensing device system 325 includes various sensing devices ortransducers configured to sense or detect a particular condition whilepositioned within a bodily cavity. In some embodiments, at least part ofthe sensing device system 325 may be provided by transducer-based devicesystem 300 (e.g., various ones of transducers 306). In some embodiments,sensing device system 325 includes various sensing devices ortransducers configured to sense or detect a particular condition whilepositioned outside a given bodily cavity or even outside a body thatincludes the bodily cavity. In some embodiments, the sensing devicesystem 325 may include an ultrasound device system or a fluoroscopydevice system or portions thereof by way of non-limiting example.

The energy source device system 340 may, for example, be connected tovarious selected transducers 306 or their respective electrodes 315 toprovide energy in the form of electric current or energy (e.g., RFenergy) to the various selected transducers 306 or their respectiveelectrodes 315 to cause ablation of tissue. In this regard, althoughFIGS. 3A and 3B show a communicative connection between the energysource device system 340 and the controller 324 (and its data processingdevice system 310), the energy source device system 340 may also beconnected to the transducers 306 or their respective electrodes 315 viaa communicative connection that is independent of the communicativeconnection with the controller 324 (and its data processing devicesystem 310). For example, the energy source device system 340 mayreceive control signals via the communicative connection with thecontroller 324 (and its data processing device system 310), and, inresponse to such control signals, deliver energy to, receive energyfrom, or both deliver energy to and receive energy from one or more ofthe transducers 306 via a communicative connection with such transducers306 or their respective electrodes 315 (e.g., via one or morecommunication lines through catheter body 314, elongated cable 316 orcatheter sheath 312) that does not pass through the controller 324. Inthis regard, the energy source device system 340 may provide results ofits delivering energy to, receiving energy from, or both deliveringenergy to and receiving energy from one or more of the transducers 306or the respective electrodes 315 to the controller 324 (and its dataprocessing device system 310) via the communicative connection betweenthe energy source device system 340 and the controller 324.

The energy source device system 340 may, for example, provide energy inthe form of electric current to various selected transducers 306 ortheir respective electrodes 315. Determination of a temperaturecharacteristic, an electrical characteristic, or both, at a respectivelocation at least proximate each of the various transducers 306 or theirrespective electrodes 315 may be made under the influence of energy orcurrent provided by the energy source device system 340 in variousembodiments. Energy provided to an electrode 315 by the energy sourcedevice system 340 may in turn be transmittable by the electrodes 315 toadjacent tissue (e.g., tissue forming a tissue wall surface). The energysource device system 340 may include various electric current sources orelectrical power sources. In some embodiments, an indifferent electrode326 is provided to receive at least a portion of the energy transmittedby at least some of the transducers 306 or their respective electrodes315. Consequently, although not shown in FIGS. 3A and 3B, theindifferent electrode may be communicatively connected to the energysource device system 340 via one or more communication lines in someembodiments. The indifferent electrode 326 is typically configured to bepositioned outside of a bodily cavity and may be positioned on anexterior body surface and, in some embodiments, although shownseparately in FIGS. 3A and 3B, is considered part of the energy sourcedevice system 340.

Structure 308 may be delivered and retrieved via a catheter member, forexample, a catheter sheath 312. In some embodiments, the structure 308provides expansion and contraction capabilities for a portion of amedical device (e.g., an arrangement, distribution or array oftransducers 306). The transducers 306 may form part of, be positioned orlocated on, mounted or otherwise carried on the structure 308 and thestructure may be configurable to be appropriately sized to slide withincatheter sheath 312 in order to be deployed percutaneously orintravascularly. FIG. 3A shows one embodiment of such a structure, wherethe elongate members 304, in some embodiments, are stacked in thedelivery or unexpanded configuration to facilitate fitting within theflexible catheter sheath 312. In some embodiments, each of the elongatemembers 304 includes a respective distal end 305 (only one called out inFIG. 3A), a respective proximal end 307 (only one called out in FIG. 3A)and an intermediate portion 309 (only one called out in FIG. 3A)positioned between the proximal end 307 and the distal end 305.Correspondingly, in some embodiments, structure 308 includes a proximalportion 308 a and a distal portion 308 b. In some embodiments, theproximal and the distal portions 308 a, 308 b include respectiveportions of elongate members 304. The respective intermediate portion309 of each elongate member 304 may include a first or front surface 318a that is positionable to face an interior tissue surface within abodily cavity and a second or back surface 318 b opposite across athickness of the intermediate portion 309 from the front surface 318 a.In some embodiments, each elongate member 304 includes a twisted portionat a location proximate proximal end 307. The transducers 306 may bearranged in various distributions or arrangements in variousembodiments. In some embodiments, various ones of the transducers 306are spaced apart from one another in a spaced apart distribution asshown, for example in at least FIGS. 3A and 3B. In some embodiments,various regions of space are located between various pairs of thetransducers 306. For example, in FIG. 3B the transducer-based devicesystem 300 includes at least a first transducer 306 a, a secondtransducer 306 b and a third transducer 306 c (all collectively referredto as transducers 306). In some embodiments, each of the first, thesecond, and the third transducers 306 a, 306 b and 306 c are adjacenttransducers in the spaced apart distribution. In some embodiments, thefirst and the second transducers 306 a, 306 b are located on differentelongate members 304 while the second and the third transducers 306 b,306 c are located on a same elongate member 304. In some embodiments, afirst region of space 350 is between the first and the secondtransducers 306 a, 306 b. In some embodiments, the first region of space350 is not associated with any physical portion of structure 308. Insome embodiments, a second region of space 360 associated with aphysical portion of device system 300 (e.g., a portion of an elongatemember 304) is between the second and the third transducers 306 b, 306c. In some embodiments, each of the first and the second regions ofspace 350, 360 do not include a transducer or electrode thereof oftransducer-based device system 300. In some embodiments, each of thefirst and the second regions of space 350, 360 do not include anytransducer or electrode.

It is noted that other embodiments need not employ a group of elongatemembers 304 as employed in the illustrated figures. For example, otherembodiments may employ a structure including one or more surfaces, atleast a portion of the one or more surfaces defining one or moreopenings in the structure. In these embodiments, a region of space notassociated with any physical portion of the structure may extend over atleast part of an opening of the one or more openings. In other exampleembodiments, other structures may be employed to support or carrytransducers of a transducer-based device provided by various flexiblecircuit structures (e.g., by various embodiments associated with, e.g.,at least FIGS. 4, 5, 6, 7, 8, 9A, 9B, 10, 11, 12 and 13). In someembodiments, an elongated catheter member may be used to distribute theflexible circuit structure-based transducers in a linear or curvilineararray. Basket catheters or balloon catheters may be used to distributethe flexible circuit structure-based transducers in a two-dimensional orthree-dimensional array.

In various example embodiments, the energy transmission surface 319 ofeach electrode 315 is provided by an electrically conductive surface. Insome embodiments, each of the electrodes 315 is located on varioussurfaces of an elongate member 304 (e.g., front surfaces 318 a or backsurfaces 318 b). In some embodiments, various electrodes 315 are locatedon one, but not both of the respective front surface 318 a andrespective back surface 318 b of each of various ones of the elongatemembers 304. For example, various electrodes 315 may be located only onthe respective front surfaces 318 a of each of the various ones of theelongate members 304. Three of the electrodes 315 are identified aselectrodes 315 a, 315 b and 315 c in FIG. 3B. Three of the energytransmission surfaces 319 are identified as 319 a, 319 b and 319 c inFIG. 3B. In various embodiments, it is intended or designed to have theentirety of each of various ones of the energy transmission surfaces 319be available or exposed (e.g., without some obstruction preventing atleast some of the ability) to contact non-fluidic tissue at least whenstructure 308 is positioned in a bodily cavity in the expandedconfiguration. In various embodiments, it is intended or designed tohave no portion of each of at least one of the energy transmissionsurfaces 319 contact fluidic tissue when the at least one of the energytransmission surfaces 319 contacts a contiguous portion of a non-fluidictissue surface (e.g., a tissue surface that defines a tissue wall).

In various embodiments, the respective shape of various electricallyconductive surfaces (e.g., energy transmission surfaces 319) of variousones of the electrodes 315 vary among the electrodes 315. In variousembodiments, one or more dimensions or sizes of various electricallyconductive surfaces (e.g., energy transmission surfaces 319) of at leastsome of the electrodes 315 vary among the electrodes 315. The shape orsize variances associated with various ones of the electrodes 315 may bemotivated for various reasons. For example, in various embodiments, theshapes or sizes of various ones of the electrodes 315 may be controlledin response to various size or dimensional constraints imposed bystructure 308.

FIG. 5 is a schematic plan view of at least one conductive layer 504 bof a transducer-based device system that includes a flexible circuitstructure 501 providing a plurality of resistive elements 509 (fourcalled out in FIG. 5 as reference symbols 509 a, 509 b, 509 c, 509 d)according to various example embodiments. It should be noted that thevarious elements and structures described above with respect to flexiblecircuit structure 401 may also be applicable to flexible circuitstructure 501. In this regard, in some embodiments, illustratedstructures having reference numerals in each of FIGS. 5-8, 9A, 9B, 10,11, 12, and 13 that end in the same digits or characters as thosecorresponding illustrated structures in FIG. 4 may represent the same oran alternate embodiment of the corresponding illustrated structure inFIG. 4. For example, in some embodiments, the electrically conductivelayer 504 b corresponds to an alternate embodiment of the electricallyconductive layer 404 b.

In some embodiments, at least (a) one or more conductive layers or (b)one or more nonconductive layers are positioned atop or overlaid on theelectrically conductive layer 504 b. A group of electrodes 515 are shownin broken lines according to some embodiments. In some embodiments, atleast some of the electrodes 515 are provided by a conductive layerother than conductive layer 504 b. In some embodiments, at least some ofthe electrodes 515 are provided by electrically conductive layer 504 a(above layer 504 b according to the perspective shown in FIG. 5). Insome embodiments, at least one nonconductive layer is located betweenconductive layers 504 a and 504 b. In some embodiments, a portion ofeach electrode 515 is positioned in an overlapping arrangement (e.g., asviewed in the plan view of FIG. 5) with a portion of at least one of theresistive elements 509. In some embodiments, a portion of each electrode515 is positioned in an overlapping arrangement (e.g., as viewed in theplan view of FIG. 5) with a portion of at least one of conductive meshes520 (described below). It is noted that an electrode (e.g., electrode315, 415 and 515) may be provided (e.g., in a similar or sameoverlapping arrangement) in at least some of the embodiments describedbelow, even where it may not be explicitly shown. In some embodiments,the at least one conductive layer 504 b is provided on, formed on or in,or supported by at least one electrically nonconductive layer 503 whichmay correspond to nonconductive flexible layer 403 b in someembodiments. In some embodiments, a plurality of nonconductive flexiblelayers may be interleaved with the electrically conductive flexiblelayers 504 a, 504 b.

In some embodiments, resistive elements 509 provide temperature sensors408 having a targeted electrical resistance (e.g., a resistance valuetargeted by an element including a particular amount of conductivematerial arranged with a particular configuration (e.g., a particular,width, length, and thickness suitable for substantially achieving thetargeted resistance within some particular error bounds). In someembodiments, portions of various leads 510 (three called out in FIG. 5as reference symbols 510 a, 510 b, and 510 c) are arranged to allow forsampling of electrical voltage between each respective resistive element509. In some embodiments, portions of various leads 510 (three calledout in FIG. 5 as reference symbols 510 a, 510 b, and 510 c) are arrangedto allow for sampling of electrical voltage across each respectiveresistive element 509. In some embodiments, the resistive elements 509are connected in series by conductive meshes 520 (three called out inFIG. 5 as reference symbols 520 a, 520 b, and 520 c) to allow electriccurrent to pass through all of the resistive elements 509. In someembodiments, the serial connection of resistive elements 509 byconductive meshes 520 provides at least one electric current flow paththrough the resistive elements 509. In some embodiments, the conductivemeshes 520 provide multiple electrical pathways for the electric currentto pass through all of the resistive elements 509.

In some embodiments, the conductive meshes 520 are connected to theresistive elements 509 by a plurality of electrical connection points.In some embodiments, each conductive mesh 520 is connected to each ofthe respective adjacent pair of resistive elements 409 by an electricalconnection point set 525 (six particular electrical connection pointsets called out in FIG. 5 as reference symbols 525 a, 525 b, 525 c, 525d, 525 e and 525 f). The electrical connection points of each of theelectrical connection point sets 525 are schematically depicted by dots“⋅” in FIG. 5. As an example, in FIG. 5, the conductive mesh 520 a isconnected to the resistive element 509 a by connection point set 525 a.The conductive mesh 520 a is also connected to the resistive element 509b by connection point set 525 b. Similarly, in FIG. 5, the conductivemesh 520 b is connected to the resistive element 509 b by connectionpoint set 525 c and to the resistive element 509 c by connection pointset 525 d. Similarly, in FIG. 5, the conductive mesh 520 c is connectedto the resistive element 509 c by connection point set 525 e and to theresistive element 509 d by connection point set 525 f. Each connectionpoint set 525 may include a plurality of electrical connection pointsconnecting the conductive mesh 520 to the resistive element 509. In someembodiments, the connection point set 525 is arranged away from anelectrode edge 515-1 (e.g., as viewed in the plan view of FIG. 5) toreduce the likelihood of cracks or open or otherwise impaired circuitsdue to flexing or other stress-imparting actions. In some embodiments,the electrical connection point set 525 is positioned within a perimeterof the electrode 515 defined at least in part by electrode edge 515-1and overlaps, or is overlapped by, the electrode 515 to reduce thelikelihood of cracks or open circuits due to flexing or otherstress-imparting actions. It is noted that various connection pointsbetween various patterned features may act as stress risers and it ispreferable, in some embodiments, to keep the connection points away fromother stress-concentrating elements such as the edge 515-1 of arelatively stiff electrode 515.

FIGS. 4 and 5 include different example embodiments of conductive meshes420 and 520. Each of the conductive meshes 420 and 520 provide aplurality of electrical pathways for the flow of electric current fromone resistive element 409, 509 to the next serially connected resistiveelement 409, 509, according to some embodiments. In some embodiments,the phrase “adjacent resistive elements” or “adjacent pair of resistiveelements” refers to a pair of resistive elements 409, 509 seriallyconnected to each other (e.g., by a same conductive mesh 420, 520 orgroup of conductive meshes (e.g., meshes 1121 b, 1121 c discussed belowwith respect to FIG. 11)), with no other resistive element 409, 509serially connected in between the two resistive elements of the adjacentpair of elements. For example, in FIG. 5, resistive elements 509 a and509 b are adjacent resistive elements. Similarly, resistive elements 509b and 509 c are adjacent resistive elements. However, resistive elements509 a and 509 c are not adjacent resistive elements, because theresistive element 509 b is serially connected between resistive element509 a and resistive element 509 b.

In some embodiments, each resistive element 409, 509 forms at least partof a respective transducer (e.g., transducer 406) and is configured toperform a specific predetermined function of the part of the respectivetransducer. For example, in various embodiments, it may be desired thateach of resistive elements 409, 509 have a serpentine form particularlysized and shaped to increase the overall electrical resistance of theresistive element while distributing portions of the resistive elementover as much of a particular area as possible. This may be motivated byvarious reasons. For example, it may be desired to distribute portionsof resistive elements 409, 509 to occupy an area having overalldimensions and an overall shape that approximate the overall dimensionsand overall shape of a respective overlapping electrode 415, 515,thereby allowing the resistance e.g., and consequently the temperature(e.g., average temperature) to be determined over a particular tissuearea and subsequently treat (e.g., via tissue ablation) the sameparticular tissue region with the electrode having a size and shape thateffectively matches the size and shape of the particular tissue region.It is understood that various interconnecting elements/structures (e.g.,leads, conductive meshes) between the resistive elements also areresistive in nature, and in some cases, their specific resistances mustbe considered. However, these interconnecting elements/structures arenot considered to be resistive elements in this disclosure and theaccompanying claims, since their function is not to directly form partof a specific transducer, but rather, act as interconnects betweenvarious transducers. Accordingly, in various embodiments, adjacentresistive elements are provided by an adjacent pair of resistiveelements (e.g., 409, 509, 609, 709, 809), the resistive elements of theadjacent pair interconnected by an interconnecting element or structure.

The conductive meshes 420, 520 are not limited to the arrangement shownin FIGS. 4 and 5 and may include any arrangement of more than oneconductive segment 430, 530 connecting two adjacent resistive elements409, 509 so as to provide multiplicity, redundancy, and failuretolerance for the electric current flow path. In some embodiments, eachof the conductive meshes 420, 520 connecting the resistive elements 409,509 in a serial electrical arrangement may have different shapes andconfigurations.

FIG. 5 also shows measurement leads 510 (three called out in FIG. 5 asreference symbols 510 a, 510 b and 510 c) connecting to respectiveconductive meshes 520. In some embodiments, the measurement leads 510are electrically connected to the conductive meshes 520 at a pluralityof electrical connection points forming a measurement lead connectionpoint set. In some embodiments, at least some of the measurement leads510 are voltage measurement leads 510 connected to a voltage measurementsystem to measure voltage across a resistive element (e.g., 409, 509,609, 709, 809). In some embodiments, at least some of the measurementleads 510 are current measurement leads 510 connected to a currentmeasurement system to measure electric current flowing through aresistive element (e.g., 409, 509, 609, 709, 809). In some embodiments,a first measurement lead 510 a is electrically connected to a firstconductive mesh 520 a at a first measurement lead connection point set511 a. The first measurement lead connection point set 511 a includesone or more electrical connection points that connect the firstmeasurement lead 510 a to the first conductive mesh 520 a. A secondmeasurement lead 510 b is electrically connected to a second conductivemesh 520 b at a second measurement lead connection point set 511 b. Thesecond measurement lead connection point set 511 b includes one or moreelectrical connection points that connect the second measurement lead510 b to the second conductive mesh 520 b. In some embodiments, thesecond measurement lead connection point set 511 b includes a greaternumber of electrical connection points than the first measurement leadconnection point set 511 a. For example, in some embodiments, asillustrated in FIG. 5, the first measurement lead connection point set511 a includes a single connection point, and the second measurementlead connection point set 511 b includes two connection points. A thirdmeasurement lead 510 c is electrically connected to a third conductivemesh 520 c at a third measurement lead connection point set 511 c. Thethird measurement lead connection point set 511 c includes one or moreelectrical connection points that connect the third measurement lead 510c to the third conductive mesh 520 c. In various embodiments, each ofthe first, the second, and the third measurement lead connection pointsets 511 a, 511 b, 511 c (collectively, electrical connection point sets511) includes a different number of connection points than at least oneother of the first, the second, and the third measurement leadconnection point sets 511 a, 511 b, 511 c. In some embodiments, firstmeasurement lead 510 a connects to the conductive mesh 520 a at oneelectrical connection point, second measurement lead 510 b connects tothe conductive mesh 520 b at two electrical connection points, and thirdmeasurement lead 510 c connects to the conductive mesh 520 c at threeelectrical connection points. In some embodiments, as shown in FIG. 5,the measurement lead 510 b branches into two measurement leads or leadportions, and the measurement lead 510 c branches into three measurementleads or lead portions, providing further multiplicity, redundancy, andfailure tolerance in case of a crack or open circuit developing in oneof the downstream portions (e.g., post-branching closer to therespective mesh 520) of the measurement leads 510. It is noted thatother embodiments may provide multiplicity, redundancy, and failuretolerance by employing multiple separate measurement leads 510, insteadof branched measurement leads 510, connected to some or all of theconductive meshes 520. Multiple separate leads 510 may improvemultiplicity, redundancy, and failure tolerance as compared to branchedleads 510, while branched leads may reduce manufacturing cost, circuitfootprint, and circuit design complexity as compared to multipleseparate leads 510.

In some embodiments, various portions of the measurement leads 510 arearranged (e.g., patterned) to provide a uniform, parallel orsubstantially parallel arrangement of various portions of themeasurement leads 510. In some embodiments, the first measurement lead510 a includes a single conductive trace that connects to the firstconductive mesh 520 a. In some embodiments, second measurement lead 510b is split into two second measurement leads or traces, a first of thetwo second measurement leads or traces being provided (e.g., patterned)in a region adjacent a region occupied by the first measurement lead 510a. In some embodiments, the two second measurement leads/traces areconnected to the second conductive mesh 520 b at two electricalconnection points. This arrangement may advantageously reduce the spacerequired by the second measurement lead 510 b in various regionsadjacent the first measurement lead 510 a while providing some degree ofredundancy should a failure occur in one of the two second measurementleads or traces 510 b. Increasing the number of measurement leadconnection points 511 for downstream meshes 520 (e.g., meshes 520further from the destination of the signals provided by the respectivemeshes 520) may be beneficial and appropriate at least because circuitconnection failures may be more likely downstream, according to someembodiments. Further, increasing the number of measurement leadconnection points 511 for downstream meshes 520 may be beneficial andappropriate at least because such a configuration may facilitatemaintaining a uniform or relatively uniform stiffness throughout thelength of the flexible circuit structure 501 by the connecting leads.For example, according to some embodiments, the first measurement lead510 a extends downstream toward the first connection point set 511 a,and a preferred location for the split in second measurement lead 510 bis in a region downstream of the first measurement lead connection pointset 511 a to take advantage of the space made available by the absenceof the first measurement lead 510 a. If such space is not filled, theremay be less structure in the flexible circuit structure 501 along thelength of the flexible circuit structure 501 in a downstream direction,which may act to varying flexibility of the circuit structure 501 in thedownstream direction and expose the circuit elements to increased stressdue to the varying flexibility. In some embodiments, a split in ameasurement lead 510 is positioned away from electrode edges 515-1 toreduce overall stress risers.

In this regard, in some embodiments, the third measurement lead 510 cbranches into three third measurement leads or traces 510 c. At leastone of the third measurement leads 510 c may be provided (e.g.,patterned) in a region vacated by the second measurement lead 510 b dueto a presence of a split in the second measurement lead 510 b. That is,if the second measurement lead 510 b was made up of two separate leads,a respective region would be required for each of the two separateleads. The branched configuration of second measurement lead 510 ballows one of these respective regions to be vacated and be, instead,occupied by the third measurement lead 510 c. In some embodiments, thethree third measurement leads/traces are connected to the thirdconductive mesh 520 c at three electrical connection points.

In some embodiments, the flexible circuit structure 501 is electricallyconnected to a voltage or current measurement circuit, discussed above,by the plurality of measurement leads 510. Respective pairs ofmeasurement leads 510 may be positioned to sense voltage across eachresistive element 509. For example, in FIG. 5, measurement leads 510 aand 510 b are positioned to sense voltage across resistive element 509b, and measurement leads 510 b and 510 c are positioned to sense voltageacross resistive element 509 c.

FIGS. 6, 7, 8, 9A, and 9B show various example embodiments of flexiblecircuit structures including multiple or redundant electric current flowpaths. It should be noted that the descriptions provided above withrespect to flexible circuit structures 401, 501 may also be applicableto various example embodiments shown in each of FIGS. 6, 7, 8, 9A, and9B, as discussed above. It should also be noted that the specific numberor arrangement of various elements (such as resistive elements,conductive meshes, electrodes, conductive segments, or measurementleads) in FIGS. 6, 7, 8, and 9 are non-limiting and provided asillustrative examples that may be beneficial in certain environments orapplications. Other example embodiments may include different numbers orarrangements of various elements. Each of the example embodiments shownin FIGS. 6, 7, 8, and 9 includes a plurality of electrical pathways toprovide multiple or alternate electric current flow paths in the eventof failure (such as a crack or other failure mechanism) of anyparticular electric current flow path.

FIG. 6 is a schematic plan view of a flexible circuit structure 601 thatincludes a conductive mesh 620 electrically connected and directlyconnected to adjacent resistive elements 609 a, 609 b (collectively 609)by electrical connection point sets 625 a, 625 b, according to variousexample embodiments. The conductive mesh 620 and resistive elements 609a, 609 b may form part of a flexible circuit structure 401, 501according to various embodiments, as discussed above. In this regard, asdiscussed above, in some embodiments, the various elements andstructures illustrated in FIG. 6 may correspond to the same or differentembodiments of such elements and structures described above with respectto FIG. 4 or any other figure herein including such elements andstructures, and vice versa. While this statement is made particularlywith respect to FIG. 6, the same applies to at least each of FIGS. 4, 5,7, 8, 9A, 9B, 10, 11, 12, and 13. For example, the various elements andstructures described above with respect to flexible circuit structure401 and 501 may also be applicable to flexible circuit structure 601. Inthis regard, the conductive meshes 420, 520, and 620 show non-limitingexamples of conductive meshes according to various embodiments.

In some embodiments, the conductive mesh 620 includes a plurality ofconductive segments 630 spatially arranged to provide a plurality ofelectrical pathways between the resistive elements of the respectiveadjacent pair of resistive elements 609 a, 609 b. For clarity of drawingand ease of discussion, the conductive segments 430, 530, 630 (or otherconductive segments described herein) may also be referred to asconductive segments S. In FIG. 6, the plurality of conductive segments Sincludes a first conductive segment set in which the segments 630thereof are each identified as segments S_(x), and a second conductivesegment set in which the segments 630 thereof are each identified assegments S_(y). Each conductive segment 630 provides a respectiveportion of each of at least some of the plurality of electricalpathways. The electrical pathways are arranged in a network between theresistive elements 609 a, 609 b of the respective adjacent pair ofresistive elements 609. In the various embodiments associated with FIG.6, each conductive segment 630 in the conductive mesh 620 is a portionof a conductive trace formed of conductor material. Each conductivesegment 630 may be patterned in an electrically conductive layer (e.g.,conductive layer 404 b, 504 b). Each conductive segment 630 may bedefined, at least in part, as including a connection point (e.g., aconnection point in the electrical connection point set 625 a, 625 b) toa resistive element 609, an intersection point (e.g., an intersectionpoint 640 (a few called out in FIG. 6)) with another conductive segment630, or an intersection point (e.g., 611) with a measurement lead 610.In the example embodiments of FIG. 6, there are four electricalconnection points in the electrical connection point set 625 a, fourelectrical connection points in the electrical connection point set 625b, and fourteen intersection points 640. For clarity of drawing, only asubset of the intersection points 640 is labeled. The electricalconnection points of each of the electrical connection point sets 625 a,625 b and the intersection points 640, 611 are schematically depicted bydots “*” in FIG. 6. Other embodiments may employ other numbers ofconductive segments 630 or other arrangements of conductive segments630. Consequently, the number of electrical connections points inelectrical connection point sets 625 a, 625 b is not limiting, and thenumbers of intersection points 640 and 611 are non-limiting.

In some embodiments, the conductive mesh 620 and its conductive segments630 exist within multiple conductive flexible circuit layers of theflexible circuit structure (e.g., 401, 501). For example, in someembodiments, the vertical conductive segments S_(y) may reside within alower conductive flexible circuit layer than the horizontal conductivesegments S_(x). In such embodiments, the intersection points 640 mayrepresent vias that pass through the different conductive flexiblecircuit layers and connect the vertical conductive segments S_(y) in thelower conductive flexible circuit layer with the horizontal conductivesegments S, in the upper conductive flexible circuit layer. In someembodiments where the resistive elements or electrical loads 609 a, 609b are be temperature sensors, the conductive mesh 620 is anelectrical-connection-arrangement that connects the respective adjacentpair of temperature sensors 609 a, 609 b by at least one via arranged toelectrically connect different ones of the conductive flexible circuitlayers. Accordingly, it is to be understood that the conductive meshesor other electrical-connection-arrangements described herein need not beentirely located within a same circuit layer. By having the conductivemesh (e.g., at least 620) or other electrical-connection-arrangementspan multiple circuit layers, additional fault tolerance may befacilitated, according to some embodiments.

It is noted that FIG. 6 includes a measurement lead 610 electricallyconnected to the conductive mesh 620 (FIG. 6 shows another measurementlead 610 passing onto another conductive mesh (not shown), according tosome embodiments) via corresponding measurement lead connection pointset 611 to measure voltage or current according to various embodiments.Typically, in these various embodiments, the impedance or resistanceassociated with the measurement lead 610 (connected to the conductivemesh 620) is made to be significantly higher than the impedance orresistance of at least the conductive mesh 620, the resistive element609 a, or the resistive element 609 b to cause the electric current toflow between resistive elements 609 a, 609 b predominately or almostentirely through conductive mesh 620 rather than through measurementlead 610 (connected to the conductive mesh 620). Therefore, in theseparticular embodiments, the measurement lead intersection point set 611may be considered separately from the set of intersection points 640.

In some embodiments, a conductive segment (e.g., 630) (a) originates at(i) an electrical connection point (e.g., a connection point of theelectrical connection point set 625) with a resistive element (e.g.,609), (ii) an intersection point (e.g., 640) with another conductivesegment (e.g., 630), or (iii) an intersection point (e.g., 611) with ameasurement lead (e.g., 610); and (b) terminates at (i) an electricalconnection point (e.g., a connection point of the electrical connectionpoint set 625) with a resistive element (e.g., 609), (ii) anintersection point (e.g., 640) with another conductive segment (e.g.,630), or (iii) an intersection point (e.g., 611) with a measurement lead(e.g., 610). The conductive segments 630 may be linear or non-linear inform, may have different shapes, and are not limited to extending in anyparticular direction.

In some embodiments, the conductive mesh 620 includes a plurality ofelectrical connection points electrically connecting a respective set ofthe plurality of conductive segments 630 to each resistive element 609a, 609 b of the respective adjacent pair of resistive elements 609. Insome embodiments, at least one of the plurality of electrical connectionpoints (e.g., an electrical connection point included in the electricalconnection point set 625 a) of the conductive mesh 620 is locatedadjacent or on one resistive element of the respective adjacent pairs ofresistive elements 609 (e.g., resistive element 609 a). The at least oneelectrical connection point may be electrically connected to at leasttwo of the plurality of electrical connection points (e.g., twoelectrical connection points included in the electrical connection pointset 625 b) located at least adjacent or on the other resistive elementof the respective adjacent pair of resistive elements 609 (e.g.,resistive element 609 b). In some embodiments, the at least two of theplurality of electrical connection points do not include any electricalconnection points in common with the at least one of the plurality ofelectrical connection points (e.g., two electrical connection points inelectrical connection point set 625 b are different than an electricalconnection point in electrical connection point set 625 a).

In some embodiments, at least one electrical connection point (e.g., atleast one electrical connection point in the electrical connection pointset 625 a) is located closer to resistive element 609 a than to at leastone other electrical connection point (e.g., at least one electricalconnection point in the electrical connection point set 625 b). Ineffect, this arrangement of electrical connection points (and otherarrangements of other embodiments described in this disclosure) providesincreased multiplicity, redundancy, and failure tolerance in particularportions of the flexible circuit structure 601 that may be susceptibleto crack under various stress-causing applications. In some embodiments,at least one electrical connection point (e.g., at least one electricalconnection point in electrical connection point set 625 a) is locatedcloser to resistive element 609 a than to each of at least twoelectrical connection points (e.g., each of at least two electricalconnection points in the electrical connection point set 625 b). The atleast one electrical connection point in set 625 a may be electricallyconnected to the at least two electrical connection points in set 625 baccording to various embodiments (e.g., via at least some of theconductive segments 630). In some embodiments, at least one electricalconnection point (e.g., at least one electrical connection point in theelectrical connection point set 625 a) is located closer to resistiveelement 609 a than a distance separating at least one other electricalconnection point (e.g., at least one electrical connection point inelectrical connection point set 625 b) and resistive element 609 a. Insome embodiments, at least one electrical connection point (e.g., atleast one electrical connection point in the electrical connection pointset 625 a) is located by a closer distance to resistive element 609 athan each of a respective distance separating each of at least two otherelectrical connection points (e.g., at least two electrical connectionpoints in electrical connection point set 625 b) and resistive element609 a. The at least one electrical connection point may be electricallyconnected to the at least two other electrical connection pointsaccording to various embodiments.

In some embodiments, the first electrical connection point set 625 a,the second electrical connection point set 625 b or each of the firstelectrical connection point set 625 a and the second electricalconnection point set 625 b includes at least two electrical connectionpoints. The plurality of electrical connection points in each of thesets 625 provides multiple or redundant electric current flow pathsthrough the plurality of electrical pathways in the flexible circuitstructure 601. If a particular electrical pathway is rendered open dueto a crack, the open pathway is deemed to not be included in an electriccurrent flow path, because electric current is not able to flow throughthe open pathway in the context of the broader circuit, according tosome embodiments.

The conductive mesh 620 may include various spatial arrangements ofconductive segments 630 that provide at least two electric current flowpaths through the conductive mesh 620 for multiplicity, redundancy, andfailure tolerance. For example, in some embodiments, the plurality ofconductive segments 630 of the conductive mesh 620 includes a firstconductive segment set in which each segment in the first conductivesegment set extends in a first direction (e.g., the first conductivesegment set whose segments are identified as S, and proceed horizontallyin FIG. 6) and a second conductive segment set in which each segment inthe second conductive segment set extends in a second direction (e.g.,the second conductive segment set whose segments are identified as S_(y)and proceed vertically in FIG. 6), the first direction (e.g., horizontalin the perspective of FIG. 6) being perpendicular or oblique to thesecond direction (e.g., vertical in the perspective of FIG. 6). In someembodiments, at least one of the conductive segments 630 in the firstconductive segment set intersects with at least one of the conductivesegments 630 in the second conductive segment set at an intersectionpoint 640 (e.g., S, conductive segments intersect S_(y) conductivesegments in the example of FIG. 6).

It is noted that the plurality of conductive segments 630 spatiallyarranged to provide a plurality of electrical pathways between theresistive elements 609 a, 609 b advantageously allows for multiplicity,redundancy, and failure tolerance that can counter various failure modesthat can occur in the interconnecting elements between the adjacent pairof resistive elements 609 a, 609 b. For example, a failure (e.g., acrack or other mechanism leading to an open circuit condition) in any ofa set of the conductive segments 630 identified as S, still permitcurrent flow between the resistive elements 609 a, 609 b. An opencircuit condition developed in any one of the conductive segments S, ismitigated by existing electrical pathways (as well asalternate/additional current paths arising as a consequence of the opencircuit condition) provided by others of the conductive segments 630that have not experienced an open circuit condition. In this regard, itis understood that various combinations of conductive segments S, andS_(y) may provide the existing electrical pathways oralternate/additional electrical pathways arising as a consequence of thefailure condition (e.g., open circuit condition). Another exampleadvantage associated with the plurality of electrical pathways providedby the plurality of conductive segments 630 allows for continuity in theability to measure voltage with the measurement lead 610 during afailure (e.g., a crack or other form of open circuit failure) in any ofa set of the conductive segments 630. For example, various ones of theconductive segments S_(y) allow measurement via the measurement lead 610(connected to the conductive mesh 620) to continue should an opencircuit failure occur in at least one of the conductive segments S_(xa),S_(xb), S_(xc), S_(xd), S_(xe). In this regard, particular ones of theconductive segments S_(y) connected to conductive segments S_(xa),S_(xb), S_(xc), S_(xd), and S_(xe) allow the measurement to be continuedat electric current bearing portions of the conductive mesh 620.

A group of electrodes 615 are shown in broken lines in FIG. 6 accordingto some embodiments. In some embodiments, at least some of theelectrodes 615 are provided by a conductive layer other than theconductive layer that at least one of the resistive elements 609 orconductive mesh 620 are formed from or in. In some embodiments, at leastsome of the electrodes 615 are provided by electrically conductivelayers 404 b. In some embodiments, at least one nonconductive layer (notshown in FIG. 6) is located between at least one of the resistiveelements 609 or conductive mesh 620 and least some of the electrodes615. In some embodiments, a portion of each electrode 615 is positionedin an overlapping arrangement (e.g., as viewed in the plan view of FIG.6) with a portion of at least one of the resistive elements 609. In someembodiments, a portion of each electrode 615 is positioned in anoverlapping arrangement (e.g., as viewed in the plan view of FIG. 6)with a portion of conductive meshes 620.

FIG. 7 is a schematic plan view of at least one conductive mesh 720electrically connected to adjacent resistive elements 709 a, 709 b(collectively, resistive elements 709) by electrical connection pointsets 725 a, 725 b (collectively, electrical connection point sets 725)according to various example embodiments. It should be noted that theconductive mesh 720 shown in FIG. 7 is shown with a thicker line ascompared to, for example, the conductive mesh 620 in FIG. 6. Thisthicker line for the conductive mesh 720 in FIG. 7 is provided merely toassist in visually distinguishing such mesh 720 from other itemsillustrated in FIG. 7 and is not intended to indicate a difference in athickness of the conductive segments 730 of the conductive mesh 720 ascompared to, e.g., the conductive mesh 620 in FIG. 6. The same commentsapply to the thicker-lined conductive meshes 820 and 920 b in FIGS. 8and 9B, respectively.

As discussed above, in some embodiments, the various elements andstructures illustrated in FIG. 7 may correspond to the same or differentembodiments of such elements and structures described above with respectto FIG. 4 or any other figure herein including such elements andstructures, and vice versa. For example, it should be noted that, insome embodiments, the various elements and structures described abovewith respect to flexible circuit structure 401, 501, and 601 maycorrespond to the respective elements and structures shown in FIG. 7, asdescribed above, or vice versa. For another example, the conductive mesh720 may correspond to conductive mesh 420, 520, or 620, or vice versa,according to various embodiments. Similarly, resistive elements 709 maycorrespond to resistive elements 409, 509, or 609, or vice versa,according to various embodiments. In some embodiments, conductive mesh720 includes a plurality of conductive segments 730 (a few called out inFIG. 7) that are similar or identical in form, function, or both formand function with the conductive segments 630 described above in FIG. 6(or other conductive segments described herein or otherwise within thescope of the present invention). The conductive mesh 720 and resistiveelements 709 a, 709 b may form part of a flexible circuit structure(e.g., flexible circuit structure 401, 501, or 601) according to variousembodiments. Each of the conductive segments 730 provides a portion ofat least one of a plurality of electrical pathways P (five called out inFIG. 7 as reference symbols P1, P2, P3, P4, and P5) between theresistive elements 709 a, 709 b of each respective adjacent pair ofresistive elements 709. It should be noted that since each of electricalpathways P1, P2, P3, P4, and P5 provides a continuous electricalconnection from resistive element 709 a to resistive element 709 b, asshown in FIG. 7, each of such electrical pathways P1, P2, P3, P4, and P5also is an electric current flow path from resistive element 709 a toresistive element 709 b, according to some embodiments. Accordingly, inembodiments where a continuous electrical connection is provided by anelectrical pathway from a first circuit element to a second circuitelement, it may also be stated that such electrical pathway is anelectric current flow path from the first circuit element to the secondcircuit element.

The conductive mesh 720 is electrically connected and directly connectedto the first resistive element 709 a by the first electrical connectionpoint set 725 a and to the second resistive element 709 b by the secondelectrical connection point set 725 b. The electrical connection pointsof each of the sets 725 a, 725 b are schematically depicted by dots “*”in FIG. 7, as with FIG. 6 above and FIGS. 8, 9A, 9B, and 10-13 describedbelow. Each of the electrical connection point sets 725 a, 725 b mayinclude a plurality of electrical connection points. For example, in theillustrated embodiment shown in FIG. 7, the first electrical connectionpoint set 725 a includes electrical connection points 725 a 1, 725 a 2,725 a 3 and 725 a 4, and the second electrical connection point set 725b includes electrical connection points 725 b 1, 725 b 2, 725 b 3, and725 b 4. Other numbers of electrical connection points may be used inother embodiments. Each electrical connection point may electricallyconnect at least two of the plurality of electrical pathways between theresistive elements 709 a, 709 b of the respective adjacent pair ofresistive elements 709 according to some embodiments. For example, invarious embodiments according to FIG. 7, electrical connection point 725a 1 connects at least four electrical pathways P1, P2, P3, and P4 toelectrical connection points in the second electrical connection pointset 725 b.

In the various example embodiments shown in FIG. 7, electrical pathwayP1 connects electrical connection points 725 a 1 and 725 b 2, electricalpathway P2 connects electrical connection points 725 a 1 and 725 b 1,electrical pathway P3 connects electrical connection points 725 a 1 and725 b 3, electrical pathway P4 connects electrical connection points 725a 1 and 725 b 4, and electrical pathway P5 connects electricalconnection points 725 a 4 and 725 b 4.

In some embodiments, a total of the plurality of electrical pathways Pprovided by the plurality of conductive segments 730 of the conductivemesh 720 exceeds a total number of the electrical connection points inthe first electrical connection point set 725 a or a total number of theelectrical connection points in the second electrical connection pointset 725 b due, at least in part, to the interconnecting arrangement ofconductive segments 730 of the conductive mesh 720. For example, each ofthe first electrical connection point set 725 a and the secondelectrical connection point set 725 b has four electrical connectionpoints, but there are more electrical pathways (and correspondingelectric current flow paths), such as at least electrical pathways P1,P2, P3, P4, and P5.

A group of electrodes 715 are shown in broken lines in FIG. 7, accordingto some embodiments. In some embodiments, at least some of theelectrodes 715 are provided by a conductive layer other than theconductive layer that at least one of the resistive elements 709 orconductive mesh 720 are formed from or in. In some embodiments, at leastsome of the electrodes 715 are provided by electrically conductivelayers 404 b. In some embodiments, at least one nonconductive layer (notshown in FIG. 7) is located between at least one of the resistiveelements 709 or conductive mesh 720 and at least some of the electrodes715. In some embodiments, a portion of each electrode 715 is positionedin an overlapping arrangement (e.g., as viewed in the plan view of FIG.7) with a portion of at least one of the resistive elements 709. In someembodiments, a portion of each electrode 715 is positioned in anoverlapping arrangement (e.g., as viewed in the plan view of FIG. 7)with a portion of conductive meshes 720. In some embodiments, ameasurement lead 710 is electrically connected to conductive mesh 720(FIG. 7 shows another measurement lead 710 passing onto anotherconductive mesh (not shown), according to some embodiments). Asdiscussed with respect to flexible circuit structure 501, suchmeasurement lead 710 (connected to conductive mesh 720) may form atleast part of a circuit to measure voltage across or current through atleast the resistive element 709 a or the resistive element 709 b.

FIG. 8 is a schematic plan view of at least one conductive mesh 820electrically connected and directly connected to adjacent resistiveelements 809 a, 809 b (collectively, resistive elements 809) byelectrical connection point sets 825 a, 825 b (collectively, electricalconnection point sets 825) according to various example embodiments. Asdiscussed above, in some embodiments, the various elements andstructures illustrated in FIG. 8 may correspond to the same or differentembodiments of such elements and structures described above with respectto FIG. 4 or any other figure herein including such elements andstructures. For example, the conductive mesh 820 may correspond to adifferent embodiment of conductive mesh 420, 520, 620, or 720 accordingto various embodiments. Similarly, resistive elements 809 may correspondto resistive elements 409, 509, 609, or 709 according to variousembodiments. It should be noted that all such correspondences betweenthe elements of various embodiments are not explicitly stated here, butwould be obvious to one skilled in the art.

The conductive mesh 820 and resistive elements 809 a, 809 b may formpart of a flexible circuit structure (e.g., flexible circuit structure401, 501, 601) according to various embodiments. The conductive mesh 820in the example embodiments of FIG. 8 includes a number of conductivesegments 830 (e.g., twenty, in these illustrated embodiments, at leastsome called out as 830 a, 830 b, 830 c, 830 c-1, 830 d, and 830 c-d)providing a plurality or set of electrical pathways Q, a subset of whichare labeled as reference symbols Q1, Q2, Q3, and Q4. As with electricalpathways P1-P5 in FIG. 7, the electrical pathways Q1-Q4 each may beconsidered all of or, a portion of, an electrical current flow pathsince they are illustrated as providing a continuous electricalconnection. It is noted that the number of conductive segments 830 shownin FIG. 8 or otherwise herein is non-limiting. According to variousexample embodiments, the conductive segments 830 or the electricalpathways Q are similar or identical in form, function, or both form andfunction with the conductive segments described herein (e.g., conductivesegments 430, 530, 630, 730 or other conductive segments describedherein), or the electrical pathways P described above, respectively.

In some embodiments, the first electrical connection point set 825 aincludes five electrical connection points 825 a 1, 825 a 2, 825 a 3,825 a 4, and 825 a 5. The second or other electrical connection pointset 825 b includes five electrical connection points 825 b, 825 b 2, 825b 3, 825 b 4, and 825 b 5, according to some embodiments. The secondelectrical connection point set 825 b does not include any electricalconnection point of the first electrical connection point set 825 a,according to some embodiments. In various example embodiments, anelectrical pathway Q1 extending between electrical connection points 825a 1 and 825 b 1 is provided by a single conductive segment 830 a. Anelectrical pathway Q2 extending between electrical connection points 825a 2 and 825 b 2 is provided by a single conductive segment 830 b,according to some embodiments. An electrical pathway Q3 betweenelectrical connection points 825 a 3 and 825 b 3 is provided by fourconductive segments each labeled 830 c, according to some embodiments.Electrical pathway Q4 between electrical connection points 825 a 3 and825 b 4 is provided by seven conductive segments (e.g., one conductivesegment labeled 830 c-1 connected to connection point 825 a 3, oneconductive segment labeled 830 c-d, and five conductive segments labeled830 d heading to connection point 825 b 4), according to someembodiments. In some embodiments, a first conductive segment 830 of theconductive mesh 820 extends along a path extending from a particularelectrical connection point in the first electrical connection point set825 a to a particular electrical connection point in the secondelectrical connection point set 825 b, the path arranged to avoidintersection along the path between the first conductive segment 830 andany other one of the conductive segments 830 of the first conductivemesh 820. In the various example embodiments of FIG. 8, the pathcorresponding to electrical pathway Q1 extends from electricalconnection point 825 a 1 to electrical connection point 825 b 1 along asingle conductive segment 830 a and does not intersect any conductivesegment along the path Q1. Similarly, the path corresponding toelectrical pathway Q2 extends from electrical connection point 525 a 2to electrical connection point 825 b 2 along a single conductive segment830 b and does not intersect any conductive segment along the pathwayQ2.

In some embodiments, at least one electrical pathway Q of the pluralityof electrical pathways (e.g., Q1-Q4) does not have a conductive segment830 in common with any other electrical pathway Q of the plurality ofelectrical pathways. For example, in the various example embodimentsshown in FIG. 8, the electrical pathways Q1 and Q2 do not have anyconductive segments 830 in common with each other or with any of variousother electrical pathways Q provided by the conductive mesh 820 (e.g.,Q3 and Q4). It is noted that in these various embodiments, one of theelectrical pathways, such as Q1 and Q2, may receive a portion of thecurrent previously flowing through the other of the electrical pathways,such as Q1 and Q2, should a failure occur (e.g., a crack leading to anopen circuit condition) in the particular conductive segment orconductive segments 830 associated with the other of the electricalpathways, Q1 and Q2.

In some embodiments, the conductive mesh 820 electrically connects therespective adjacent pair of resistive elements 809 a, 809 b via arespective plurality of conductive segments 830. Each conductive segment830 of at least some of the respective plurality of conductive segments830 may be arranged to provide an unbranched pathway extendingcontinuously between the first resistive element 809 a and the second orother resistive element 809 b of the respective adjacent pair ofresistive elements 809. For example, each of single conductive segments830 a and 830 b provides a respective unbranched pathway extendingcontinuously between resistive element 809 a and resistive element 809b.

In some embodiments, a first group of the plurality of conductivesegments 830 of the conductive mesh 820 are arranged in a branchedarrangement extending from a particular electrical connection point(e.g., electrical connection point 825 a 3 in the first electricalconnection point set 825 a) to at least two particular electricalconnection points (e.g., electrical connection points 825 b 3, 825 b 4in the second electrical connection point set 825 b). In various exampleembodiments shown in FIG. 8, the group of conductive segments 830 (i.e.,conductive segments 830 c-d, 830 c, and five of the six conductivesegments 830 d) corresponding to electrical pathways Q3 and Q4 arearranged in such a branched arrangement. It is noted in variousembodiments that at least two different ones of the electrical pathwaysQ (e.g., at least two of the electrical pathways Q extending fromdifferent electrical connection points in the first electricalconnection point set 825 a or at least two of the electrical pathways Qextending to different electrical connection points in the secondelectrical connection point set 825 b) may all pass through at least onesame conductive segment (e.g., conductive segment 830 c-1). In thisregard, the at least one same conductive segment may be, for example,conductive segment 830 c-1, and may form part of two or more differentelectrical pathways. For instance, each of the electrical pathways Q3and Q4 extend or pass through a same conductive segment 830 c-1 in FIG.8.

In some embodiments, a first group of the plurality of conductivesegments 830 of the conductive mesh 820 are arranged in a branchedarrangement extending from a first particular electrical connectionpoint (e.g., electrical connection point 825 a 3 in the first electricalconnection point set 825 a) to a second particular electrical connectionpoint (e.g., electrical connection point 825 b 3). An example of such abranched arrangement, with respect to FIG. 8, is the group of conductivesegments 830 c corresponding to electrical pathway Q3, and a group ofconductive segments 830 corresponding to electrical pathway Q4, but,instead, proceeding vertically up (with respect to the orientation ofFIG. 8) to the right-most (with respect to the orientation of FIG. 8)intersection point 840 to re-join electrical pathway Q3 to connect toelectrical connection point 825 b 3.

In some embodiments, each of at least some of the plurality ofconductive segments 830 (e.g., conductive segment 830 a or conductivesegment 830 b) of the conductive mesh 820 are arranged to provide arespective unbranched electrical pathway extending continuously betweena first resistive element 809 a of the respective adjacent pair ofresistive elements 809 and a second resistive element 809 b of therespective adjacent pair of resistive elements 809. In some embodiments,at least some of the plurality of conductive segments 830 of theconductive mesh 820 are arranged to provide a branched electricalpathway extending continuously between a first resistive element 809 aof the respective adjacent pair of resistive elements 809 and a secondresistive element 809 b of the respective adjacent pair of resistiveelements 809.

It is noted, according to various embodiments, that electric currentflowing through an electric current flow path, which may include one ormore of the electrical pathways (e.g., P, Q) provided by various ones ofthe conductive meshes (e.g., at least conductive meshes, 420, 520, 620,720, 820 et cetera) described herein or otherwise within the scope ofthe present invention, will typically follow the path of leastresistance between the respective pair of resistive elements. In thisregard, typically “straight-line” arrangements of one or more of theconductive segments (e.g., conductive segments 430, 530, 630, 730, 830et cetera) between the respective pair of resistive elements willtypically provide the preferred or predominant electric current flowpath for electric current flowing through the conductive mesh due totheir relatively shorter lengths (i.e., the cross-sectional areas of theconductive segments set aside for ease of discussion). That is, ashorter straight-line electric current flow path connecting a respectivepair of resistive elements will typically have less resistance orimpedance associated with it than a longer electric current flow path(e.g., including a non-straight line electrical pathway) between therespective pair of resistive elements. Nonetheless, minor variationsamong the respective resistances or impedances of various ones of theconductive segments (e.g., conductive segments 430, 530, 630, 730, 830et cetera) may cause at least some of the electric current flow paths todeviate from following straight-line electrical pathways to follow,instead non-straight line electrical pathways (e.g., electrical pathwayQ4 is an example of a non-straight line electrical pathway), althoughthe current levels in the non-straight line electrical pathways may beof lower levels than in the straight-line electrical pathways. It isunderstood, according to various embodiments, that a failure (e.g., astress crack) that results in an open circuit condition in at least oneof the conductive segments (e.g., conductive segments 430, 530, 630,730, 830 et cetera) may result in a new electric current flow path, orenhance an existing electric current flow path, along another electricalpathway (e.g., a non-straight line electrical pathway such as each ofelectrical pathway Q4). It is further noted that a fully open circuitcondition need not be developed in at least one of the conductivesegments (e.g., conductive segments 430, 530, 630, 730, 830 et cetera)to result in a new electric current flow path or enhance an existingelectric current flow path along another electrical pathway (e.g., anon-straight line electrical pathway such as shown by electrical pathwayQ4). For example, a partial crack may develop through at least one ofthe conductive segments (e.g., conductive segments 430, 530, 630, 730,830 et cetera) that does create a fully open circuit condition butcreates a localized high impedance region adjacent the partial crack. Ifthe localized high impedance region creates an impedance along the atleast one conductor (e.g., conductive segments 430, 530, 630, 730, 830et cetera) that is larger than the impedance of the at least oneconductor prior to the creation of the localized high impedance region,a new electric current flow path or an enhanced existing electriccurrent flow path may arise along another electrical pathway (e.g., anon-straight line electrical pathway such as shown by electrical pathwayQ4).

Having a mix of branched electrical pathways (e.g., electrical pathwaysQ3, Q4 shown in FIG. 8) and non-branched electrical pathways (e.g., eachof electrical pathways Q1, Q2 shown in FIG. 8) (or as described withrespect to FIG. 9B, below) may be beneficial when a balance needs to bemade between connection redundancy and design constraints. For example,if a region of a circuit is dense with many circuit components in arelatively small area or volume, it may be beneficial to address thisdensity by implementing one or more unbranched connections in the denseregion, because the unbranched connections typically require a smalleramount of space or volume than branched connections. However, in arelatively less dense region of a circuit, where sufficient spaceexists, branched connections may be desirable to provide connectionredundancy.

In some embodiments, the conductive segments 830 are arranged so thateach of the conductive segments 830 does not contact any otherconductive segment 830 in a region spanning an edge of the resistiveelements 809 a, 809 b of the respective adjacent pair of resistiveelements 809 electrically connected by the conductive mesh 820. Such anedge of a resistive element (e.g., 809 a) may be defined as a linethrough the connection points in the connection point set (e.g., 825 a)that connects the resistive element to conductive segments 830 of themesh 820.

It is noted that various intersection points 840 connecting various onesof the conductive segments 830 are preferably, according to variousembodiments, located away from an electrode edge e.g., 815-1 of anyoverlapping electrode 815 to reduce the likelihood of stress cracking ofthe various conductive elements (e.g., conductive segments 830) due tovarious mechanical movements such as flexing. In some cases, variousintersection points 840 where several of the segments 830 meet orconnect may act as stress risers that may act as a focal point for thedevelopment of stress fractures. Likewise, as described above in thisdisclosure, the edge e.g., 815-1 of a relatively stiff electrode 815 mayalso act as a similar form of stress riser since the flexible circuitstructure is prone to bend in a step-bend manner rather than in acontinuous uniform curve due to the electrode having a relatively higherstiffness than an adjacent portion of the flexible circuit structurethat extends outwardly from the electrode edge 815-1. In this regard, itmay be advantageous to avoid combining both these stress riser effectsby creating a lateral separation between the electrode edges 815-1 andthe various intersection points 840, according to some embodiments.

The conductive mesh 820 may, according to various embodiments,electrically connect the respective adjacent pair of resistive elements809 a, 809 b via the respective plurality of electrical pathways Qelectrically connected to a respective pair of electrical connectionpoints (e.g., a pair of connection points including a connection pointfrom connection point set 825 a and a connection point from connectionpoint set 825 b). In various embodiments, each respective pair ofelectrical connection points of the respective plurality of pairs ofelectrical connection points is different than every other pair ofelectrical connection points of the respective plurality of pairs ofelectrical connection points. For example, each of electrical pathwaysQ1 and Q2 extends between a respective pair of the electrical connectionpoints (i.e., each respective pair includes an electrical connectionpoint from the first electrical connection point set 825 a and anelectrical connection point from the second electrical connection pointset 825 b), the pair of electrical connection points associated withelectrical pathway Q1 is different than the pair of electricalconnection points associated with electrical pathway Q2. Specifically,in some embodiments associated with FIG. 8, electrical pathway Q1extends from electrical connection point 825 a 1 to electricalconnection point 825 b 1, and electrical pathway Q2 extends fromelectrical connection point 825 a 2 to electrical connection point 825 b2. In some embodiments, at least one respective pair of electricalconnection points of the respective plurality of pairs of electricalconnection points includes a same electrical connection point as anotherrespective pair of the electrical connection points of the respectiveplurality of pairs of electrical connection points. For example, in theexample embodiments shown in FIG. 8, each of electrical pathways Q3 andQ4 extends between a respective pair of the electrical connection points(i.e., each respective pair includes an electrical connection point fromthe first electrical connection point set 825 a and an electricalconnection point from the second electrical connection point set 825 b),the pair of electrical connection points associated with electricalpathway Q3 including a same electrical connection point of the pair ofelectrical connection points associated with electrical pathway Q4(i.e., electrical connection point 825 a 3 of the first electricalconnection point set 825 a).

A group of electrodes 815 are shown in broken lines in FIG. 8, accordingto some embodiments. In some embodiments, at least some of theelectrodes 815 are provided by a conductive layer other than aconductive layer that at least one of the resistive elements 809 orconductive mesh 820 are formed from or in. In some embodiments, at leastsome of the electrodes 815 are provided by electrically conductive layer404 a. In some embodiments, at least one nonconductive layer is locatedbetween at least one of the resistive elements 809 or conductive mesh820 and least some of the electrodes 815. In some embodiments, a portionof each electrode 815 is positioned in an overlapping arrangement (e.g.,as viewed in the plan view of FIG. 8) with a portion of at least one ofthe resistive elements 809. In some embodiments, a portion of eachelectrode 815 is positioned in an overlapping arrangement (e.g., asviewed in the plan view of FIG. 8) with a portion of conductive meshes820. A measurement lead 810 is electrically connected to conductive mesh820 (FIG. 8 shows another measurement lead 810 passing onto anotherconductive mesh (not shown), according to some embodiments). Asdiscussed with respect to flexible circuit structure 501, suchmeasurement lead 810 (connected to conductive mesh 820) may form atleast part of a circuit to measure voltage across or current through atleast the resistive element 809 a or the resistive element 809 b.

FIGS. 9A and 9B are schematic plan views of at least various conductivemeshes 920 a, 920 b according to various example embodiments. Conductivemesh 920 a, shown as per example embodiments according to FIG. 9A,electrically connects a respective pair of adjacent resistive elements909 a 1, 909 a 2, and includes conductive segments 930 a that do notintersect or otherwise meet each other in a region between a particularedge of the resistive element 909 a 1 and a particular edge of theresistive element 909 a 2 adjacent the particular edge of the resistiveelement 909 a 1. As discussed above, in some embodiments, the variouselements and structures illustrated in FIGS. 9A and 9B may correspond tothe same or different embodiments of such elements and structuresdescribed above with respect to FIG. 4 or any other figure hereinincluding such elements and structures. For example, the conductivesegments in FIGS. 9A, 9B may be similar or identical in form, function,or both form and function with the conductive segments (430, 530, 630,730, 830, or other conductive segments) described herein or otherwisewithin the scope of the present invention according to various exampleembodiments. The conductive segments 930 a of conductive mesh 920 aterminate at electrical connection points connecting the conductive mesh920 a to the resistive elements 909 a 1 and 909 a 2 (collectively,resistive elements 909 a), according to some embodiments. In FIG. 9B,the conductive mesh 920 b electrically connects the respective adjacentpair of resistive elements 909 b 1, 909 b 2 (collectively, resistiveelements 909 b) via a respective plurality of conductive segments 930 b(only some labeled in FIG. 9B for clarity). Conductive mesh 920 b, shownin the example embodiment of FIG. 9B, includes conductive segments 930 bthat are arranged in various branched (e.g., electrical pathways R2 andR3) and unbranched arrangements (e.g., electrical pathway R1). A groupof conductive segments of at least some of the respective plurality ofconductive segments 930 b are arranged to provide a plurality ofbranched electrical pathways (e.g., R2, R3 and R4, R5 in FIG. 9B)extending continuously between the first resistive element 909 b 1 andthe second resistive element 909 b 2 of the respective adjacent pair ofresistive elements 909 b according to some embodiments. As discussedwith respect to the earlier figures, because the electrical pathwaysR1-R5 in FIG. 9B are continuous, they may be considered electric currentflow paths.

In this regard, in some embodiments, each of the unbranched or branchedpathways provides a set of potential electric current flow paths betweenthe respective adjacent pair of resistive elements. Flow of electriccurrent through these potential electric current flow paths may beaffected by the inherent impedances of each of the plurality ofelectrical pathways, making certain electric current flow paths morelikely than others. Cracks or other defects, whether partial orcomplete, may change the impedance associated with a particularelectrical pathway, and increase or decrease the likelihood of aparticular electrical pathway providing an active electric current flowpath. Cracks or other defects, whether partial or complete, may changethe impedance associated with a particular electrical pathway, and alterhow much electric current flows through a particular electrical pathway.In some embodiments, an active electric current flow path is a group ofone or more electrical pathways through which electric current isflowing. In some embodiments, the amount of electric current flowingthrough an active electric current flow path is greater than a minor orparasitic amount of current flowing through inactive electric currentflow paths.

In the example embodiments shown in FIG. 9A, each of the electricalpathways corresponding to conductive segments 930 a of conductive mesh920 a may have a substantially similar likelihood of being activeelectric current flow paths in the absence of cracks or other defects inthe electrical pathways. In the example embodiments shown in FIG. 9B,electrical pathway R1 may have a higher likelihood of being an activeelectric current flow path than electrical pathway R2. In someembodiments, both electrical pathways R1, R2 may form active electriccurrent flow paths based on the inherent impedances associated with eachof the pathways R1, R2. In some embodiments, the majority of theelectric current flowing through the conductive mesh 920 b may beflowing through electrical pathway R1 with only a minor amount ofcurrent flowing through electrical pathway R2. It should be noted thatthe conductive meshes 920 a, 920 b and resistive elements 909 a 1, 909 a2, 909 b 1, and 909 b 2 may form part of a flexible circuit structure(e.g., flexible circuit structure 401, 501) according to variousembodiments.

FIG. 10 shows a schematic plan view of the conductive mesh 1020 definedby a plurality of conductive segments 1030 (three called out as 1030,and two called out as 1030 a, 1030 b, in FIG. 10). It is noted that thenumber of conductive segments 1030 shown in FIG. 10 is non-limiting. Asdiscussed above, in some embodiments, the various elements andstructures illustrated in FIG. 10 may correspond to the same ordifferent embodiments of such elements and structures described abovewith respect to FIG. 4 or any other figure herein including suchelements and structures. For example, the conductive segments 1030 maybe similar or identical in form, function, or both form and functionwith the conductive segments (430, 530, 630, 730, 830, 930 or otherconductive segments) described herein or otherwise within the scope ofthe present invention according to various example embodiments.According to some embodiments, conductive mesh 1020 electricallyconnects a respective adjacent pair of the resistive elements 1009 a,1009 b (collectively 1009) via a respective plurality of electricalpathways. Each of the electrical pathways may be provided by arespective arrangement of one or more of the conductive segments 1030according to various embodiments (e.g., as described above with respectto FIGS. 5-9 and otherwise in this disclosure). At least a part of oneelectrical pathway of the plurality of electrical pathways may beprevented from merging with at least part of another electrical pathwayof the plurality of electrical pathways by a region of electricallynonconductive material between the part of the one electrical pathwayand the part of the another electrical pathway. For example, as shown inFIG. 10, a region 1003 b of a nonconductive material, substrate, orlayer (e.g., electrically nonconductive layer 403 b shown in FIG. 4) onor in which at least some of the conductive segments 1030 are patternede.g., may be located between two of the conductive segments (e.g.,conductive segment 1030 a and conductive segment 1030 b) and separatethem or prevent them from merging. The conductive mesh 1020 andresistive elements 1009 a, 1009 b may form part of a flexible circuitstructure (e.g., at least flexible circuit structure 401, 501),according to various embodiments.

In various embodiments associated with FIG. 10, various regions betweenthe conductive segments 1030 may form openings 1010 (three called out inFIG. 10) in the conductive mesh 1020. In some embodiments, each of theopenings 1010 may include or expose a respective region of electricallynonconductive material (e.g., a region of a nonconductive material,layer, or substrate (e.g., an electrically nonconductive layer 403, suchas layer 403 b) on or in which at least some of the conductive segments1030 are patterned on or in). In some embodiments, each of the openings1010 may surround or border a respective region of electricallynonconductive material (e.g., a region 1003 b of a nonconductivematerial (e.g., a region of electrically nonconductive layer 403 b)).

In some embodiments, the conductive mesh 1020 extends along a firstdirection 1020A from a first resistive element 1009 a toward a secondresistive element 1009 b. The conductive mesh 1020 may also extend alonga second direction 1020B orthogonal to the first direction 1020Aaccording to some embodiments. The openings 1010 may be arranged orarrayed along the first direction 1020A and the second direction 1020Baccording to various embodiments. In some embodiments, a first group ofopenings (e.g., at least openings 1010 a) may be arranged or arrayedalong the first direction 1020A and a second group of openings (e.g., atleast openings 1010 b) may be arranged or arrayed along the seconddirection 1020B. The first and the second groups of openings (e.g.,openings 1010 a and openings 1010 b, respectively) may share at leastone opening 1010 ab of the plurality of openings 1010, according to someembodiments. It should be noted that the conductive mesh 1020 andresistive elements 1009 a, 1009 b may form part of a flexible circuitstructure (e.g., at least flexible circuit structure 401, 501) accordingto various embodiments.

As will be described in more detail below with respect to FIGS. 11, 12,and 13, in some embodiments, a spacing between transducers (or otherresistive element) of a first adjacent pair of transducers (or otherresistive element) provided by a flexible circuit structure may bedifferent than a spacing between the transducers (or other resistiveelement) provided by a second adjacent pair of transducers (or otherresistive element) provided by a flexible circuit structure (such as anyof those described herein or otherwise within the scope of the presentinvention). In some embodiments, the locations of various transducers,or at least a part thereof (e.g., electrodes, such as 415, 515, 615,715, or 815 or various resistive elements such as 409, 509, 609, 709,809, 909 a, 909 b, or 1009 according to various example embodiments) inthe flexible circuit structure may be constrained by various functional,geometrical, or spatial constraints. For example, due to the geometry ofa catheter or transducer-based device system (e.g., system 200 or 300 inFIGS. 2 and 3, respectively), it may not be possible to place electrodes415 at certain locations of the elongate members 304. For example, atleast two elongate members 304 may cross one another at in a particularcrossing region. Such a crossing may prevent the placement of anelectrode in the crossing region on the underlying elongate member 304.Accordingly, a larger gap between a first adjacent pair of electrodes,transducers, or other resistive elements (e.g., that span the crossingregion where no electrode exists on the underlying elongate member 304in the above example) may exist along the length of an elongate member304 (e.g., the underlying elongate member 304 in the above example)compared to a second adjacent pair along the length (e.g., where nocrossing region exists) of the elongate member 304 (e.g., the underlyingelongate member 304). This increased distance between the first adjacentpair compared to the second adjacent pair (e.g., along the same elongatemember 304) requires a longer than usual length of an interconnectingconductive structure, such as one or more conductive meshes (420, 520,620, or any other conductive mesh described herein or otherwise withinthe scope of the present invention), to connect the first adjacent pairas compared to the second adjacent pair. This increased length may causeincreased resistance, which may skew corresponding voltage or currentmeasurements of the first adjacent pair of resistive elements. Asdescribed above, such measurements may be performed by a plurality ofmeasurement leads (e.g., measurement leads 510 or other measurementleads described herein or otherwise within the scope of the presentinvention) placed between the first adjacent pair of resistive elementsto appropriately measure at least the voltage across, or current througheach resistive element of the first adjacent pair of resistive elementsor the voltage across, or current through a portion of theinterconnecting conductive structure spanning two of the measurementleads. In some embodiments, groups of the measurement leads may beconnected to a conductive mesh to provide enhanced resistance tobending- or flexing-based failures as described above.

FIGS. 11, 12, and 13 illustrate, among other things, various embodimentsof the above-discussed differences in resistive element spacing. In thisregard, FIGS. 11, 12, and 13 show schematic plan views of a flexiblecircuit structure 1101, 1201, 1301, respectively, according to variousexample embodiments. As discussed above, in some embodiments, thevarious elements and structures illustrated in FIGS. 11, 12, and 13 maycorrespond to the same or different embodiments of such elements andstructures described above with respect to FIG. 4 or any other figureherein including such elements and structures. For example, in someexample embodiments, the various elements and structures described abovewith respect to each of flexible circuit structures 401, 501, and 601may correspond to the respective elements and structures of flexiblecircuit structures 1101, 1201, 1301. For example, each of flexiblecircuit structures 1101, 1201, 1301 may exhibit at least part of thealternating conductive/nonconductive layering (404/403) structure shownin FIG. 4, even though such a structure may not be apparent from theplan view of FIGS. 11, 12, and 13. (The same applies for flexiblecircuit structures 501 and 601, as well as the devices of FIGS. 7, 8,9A, 9B, and 10.) For another example, theelectrical-connection-arrangements 1120, 1220, 1320 may correspond toconductive meshes 420, 520, 620, 720, 820, 920, and 1020 according tovarious embodiments. Similarly, for yet another example, the electricalloads 1109, 1209, 1309 may correspond to resistive elements 409, 509,609, 709, 809, 909 a, 909 b, and 1009 according to various embodiments.

FIG. 11 is a schematic plan view of a flexible circuit structure 1101that includes at least an electrically conductive flexible circuit layer1104 formed of electrically conductive material. The electricallyconductive flexible circuit layer 1104 is provided at least proximateto, formed on or in, or supported directly or indirectly by a flexiblenonconductive layer 1103. In some embodiments, the flexible circuitstructure 1101 includes a plurality of electrical loads 1109 (threecalled out in FIG. 11 as reference symbols 1109 a, 1109 b and 1109 c).In some embodiments, the electrically conductive layer is patterned toprovide a plurality of electrical loads 1109 (three called out in FIG.11 as reference symbols 1109 a, 1109 b and 1109 c). The electrical loads1109 are electrically connected in series by a plurality ofelectrical-connection-arrangements 1120 (two called out in FIG. 11 asreference symbols 1120 a and 1120 b) according to various embodiments.Each electrical-connection-arrangement 1120 electrically connects arespective adjacent pair of electrical loads 1109 together according tosome embodiments. In some embodiments, eachelectrical-connection-arrangement 1120 directly connects each electricalload 1109 of a respective adjacent pair of electrical loads 1109 via twoor more electrical connection points 1125 (ten called out in FIG. 11). Aplurality of measurement leads 1110 (five called out in FIG. 11 asreference symbols 1110 a, 1110 b, 1110 c, 1110 d and 1110 e) are eachelectrically connected to at least one of the plurality of electricalloads 1109 (e.g., via electrical connection arrangement 1120) accordingto some embodiments. In some embodiments, the measurement leads 1110 areemployed to measure voltage across various ones of the loads and may bealso referred to as electrical-load-voltage-measurement leads 1110. Insome embodiments, the measurement leads 1110 are employed to measurecurrent flowing through various ones of the loads and may be alsoreferred to as electrical-load-current-measurement leads 1110. Each ofthe measurement leads 1110 may be directly connected to a respectiveelectrical-connection-arrangement 1120 according to various embodiments.It is noted that the respective numbers of electrical loads 1109,electrical-connection-arrangement 1120, measurement leads 1110 andelectrical connection points 1125 shown in FIG. 11 is non-limiting.

Flexible circuit structure 1101 may include arrangements where adjacentpairs of electrical loads 1109 may be separated by varying distances. Insome embodiments, a first electrical-connection-arrangement 1120 a ofthe plurality of electrical-connection-arrangements 1120 spans a firstdistance D1 between the first respective adjacent pair of electricalloads 1109 a, 1109 b of the plurality of electrical loads 1109. A secondelectrical-connection arrangement 1120 b of the plurality ofelectrical-connection-arrangements spans a second distance D2 between asecond respective adjacent pair of electrical loads 1109 b, 1109 c ofthe plurality of electrical loads 1109. In some embodiments, the firstdistance D1 and the second distance D2 are different. In someembodiments, the second distance D2 is greater than the first distanceD1. In some embodiments, the first electrical-connection-arrangement1120 a is electrically connected to a first set of one or more of theplurality of measurement leads 1110 and the secondelectrical-connection-arrangement 1120 b is electrically connected to asecond set of one or more of the plurality of measurement leads 1110. Insome embodiments, the first set of measurement leads 1110 may have adifferent number of leads than the second set of measurement leads 1110.For example, in FIG. 11, the first electrical-connection-arrangement1120 a is electrically connected and directly connected to measurementlead 1110 b, and the second electrical-connection-arrangement 1120 b iselectrically connected and directly connected to a greater number of themeasurement leads 1110 than the number of the plurality of measurementleads 1110 connected to by the first electrical-connection-arrangement1120 a. In some embodiments, the first electrical-connection-arrangement1120 a is electrically connected and directly connected to one of theplurality of measurement leads 1110 (e.g., measurement lead 1110 b) andthe second electrical-connection-arrangement 1120 b is electricallyconnected to a greater number of the plurality ofelectrical-load-voltage-measurement leads (e.g., measurement leads 1110c, 1110 d) than the number of the plurality of measurement leads 1110connected to by the first electrical-connection-arrangement 1120 a. Itis noted that various ones of the measurement leads 1110 may have abranched structure. For example, measurement lead 1110 c includes twobranched portions, each of the two branched portions directly connectedand electrically connected to electrical-connection-arrangement 1120 b(e.g., via conductive mesh 1121 b), and measurement lead 1110 d includesthree branched portions, each of the three branched portions directlyconnected and electrically connected toelectrical-connection-arrangement 1120 b (e.g., via conductive mesh 1121c).

In some embodiments, the first electrical-connection-arrangement 1120 ais electrically connected to a first measurement lead set including atleast one of the plurality of measurement leads 1110 and the secondelectrical-connection-arrangement 1120 b is electrically connected to asecond measurement lead set comprising at least two of the plurality ofmeasurement leads 1110. The second measurement lead set may have agreater number of measurement leads 1110 than the first measurement leadset according to various embodiments.

The electrical-connection-arrangements 1120 may have an inherentelectrical resistance provided by the conductive material of theelectrical-connection-arrangements 1120. In some embodiments, theelectrical resistance of the second electrical-connection-arrangement1120 b is greater than the electrical resistance of the firstelectrical-connection-arrangement 1120 a, due at least to the longerlength D2 of the second electrical-connection-arrangement 1120 b ascompared to the length D1 of the first electrical-connection-arrangement1120 a. The resistance of a particular electrical conductor is typicallydirectly proportional to a length of the electrical conductor andinversely proportional to a cross-sectional area of the electricalconductor (i.e., the cross-section as viewed in a direction of theelectric current flow in the electrical conductor). Accordingly, invarious embodiments in which the first electrical-connection-arrangement1120 a and the second electrical-connection-arrangement 1120 b areprovided by various patterned electrical conductive structures, therelatively longer length of the second electrical-connection-arrangement1120 b required to span the distance D2 will typically cause the secondelectrical-connection-arrangement 1120 b to have a greater electricalresistance than the electrical resistance of the “relatively shorter”first electrical-connection-arrangement 1120 a which spans distance D1.

In some embodiments, at least one of theelectrical-connection-arrangements 1120 may include one or moreconductive meshes 1121 (three called out in FIG. 11 as reference symbols1121 a, 1121 b and 1121 c). The conductive meshes 1121 may include aplurality of conductive segments 1130 (six called out in FIG. 11)spatially arranged to provide a plurality of electrical pathwaysdefining a respective portion of an electric current flow path betweenthe electrical loads of a respective adjacent pair of electrical loads1109 in a manner similar to or identical to that of the conductivesegments of various ones of the conductive meshes described earlier inthis disclosure. Each conductive segment of the plurality of conductivesegments provides a respective portion of the plurality of electricalpathways.

The first and the second electrical-connection-arrangements 1120 a, 1120b may include different numbers of conductive meshes 1121 as per variousexample embodiments. For example, the firstelectrical-connection-arrangement 1120 a includes one conductive mesh1121 a and the second electrical-connection-arrangement 1120 b includestwo conductive meshes 1121 b and 1121 c in FIG. 11, according to someembodiments. In some embodiments, a total of the conductive meshes 1121comprised by the second electrical-connection-arrangement 1120 b isgreater than a total of the conductive meshes 1121 comprised by thefirst electrical-connection-arrangement 1120 a. In some embodiments,each conductive mesh 1121 is directly connected and electricallyconnected to at least a respective one of the plurality ofmeasurement-leads 1110. For example, the first conductive mesh 1121 a isdirectly connected to the measurement lead 1110 b, the second conductivemesh 1121 b is directly connected to the measurement lead 1110 c, andthe third conductive mesh 1121 c is directly connected to themeasurement lead 1110 d in FIG. 11. In some embodiments, there is adifference between electrically connected and directly connected. Forexample, resistive element 1109 a is electrically connected to resistiveelement 1109 b through the first electrical-connection-arrangement 1120a. However, resistive element 1109 a is not directly connected toresistive element 1109 b as they do not share a common electricalconnection point. In contrast, resistive element 1109 a is electricallyand directly connected to the first electrical-connection-arrangement1120 a through the plurality of electrical connection points shared bythe resistive element 1109 a and the firstelectrical-connection-arrangement 1120 a.

Directly connecting, electrically connecting, or both directly andelectrically connecting a set of the measurement leads 1110 to one ofthe electrical-connection-arrangements 1120 (e.g., secondelectrical-connection-arrangement 1120 b in FIG. 11) may be motivated byvarious reasons according to some embodiments. For example, a voltageacross a particular one of the electrical loads 1109, or a currentflowing through a particular one of the electrical loads 1109, may bemeasured by a respective pair of the measurement leads 1110, theparticular one of the electrical loads 1109 positioned between themeasurement leads of the respective pair of the measurement leads 1110.To simplify the measurement circuitry, successive pairs of themeasurement leads 1110 may share a common measurement lead 1110 locatedbetween a respective adjacent pair of electrical loads 1109. Forexample, according to some embodiments associated with FIG. 11, a firstpair of measurement leads 1110 a and 1110 b are electrically connectedto electrical load 1109 a to measure a voltage thereacross, and a secondpair of measurement leads 1110 b, 1110 c are electrically connected toelectrical load 1109 b (i.e., adjacently located to electrical load 1109a) to measure a voltage thereacross, the first and the second pairs ofmeasurement leads including a same measurement lead (i.e., measurementlead 1110 b). This architecture may be particularly effective when theresistance or impedance associated with a respective connectionarrangement between each measurement lead of the pair of the measurementleads 1110 and the respective electrical load 1109 is sufficiently lowso as to not increase measurement errors beyond acceptable bounds in themeasured voltage across the respective electrical load 1109. It is notedthat each measurement lead of the pair of measurement leads 1110 may beelectrically coupled via a portion of a respectiveelectrical-connection-arrangement 1120 to the corresponding orrespective electrical load 1109. For example, in FIG. 11, measurementlead 1110 b is electrically connected to electrical load 1109 a via aportion of electrical-connection-arrangement 1120 a. Accordingly, if theresistance or impedance of an electrical-connection-arrangement 1120between two adjacent ones of the electrical loads 1109 is relativelyhigh (e.g., 5% or greater than the resistance or impedance of each atleast one of the adjacent electrical loads 1109 according to someembodiments; 2% or greater than the resistance or impedance of each atleast one of the adjacent electrical loads 1109 according to otherembodiments; or 1% or greater than the resistance or impedance of eachat least one of the adjacent electrical loads 1109 according to yetother embodiments), the use of a common or shared measurement lead 1110between the adjacent electrical loads 1109 may not be appropriate. Inthis regard, a plurality of measurement leads (e.g., the pair ofmeasurement leads 1110 c and 1110 d) may be employed between theadjacent pair of the electrical loads to reduce potential error causingfactors that may be associated with theelectrical-connection-arrangement 1120 therebetween. Again, it is notedthat an electrical-connection-arrangement 1120 may have a relativelyhigh associated resistance or impedance when it is required to span arelatively large distance (e.g., D2) between the respective two adjacentelectrical loads 1109.

It is noted that, in FIG. 11 the use of various ones of the conductivemeshes 1121 may be employed to mitigate or reduce various failure modesinduced by, for example, stress-induced cracking as described in thisdisclosure, in some example embodiments.

It is also noted that, in FIG. 11, a reduced or more minimal conductivesegment arrangement may be provided to connect conductive meshes 1121 b,1121 c and span a gap lacking a resistive element between them. In FIG.11, two parallel straight conductive segments are illustrated asconnecting conductive meshes 1121 b, 1121 c, and these two conductivesegments exhibit less complexity than each of the conductive meshes 1121b, 1121 c. Such an arrangement may be beneficial due to particulardesign constraints (e.g., presence of other circuit elements). Byproviding two parallel straight conductive segments (instead of, forexample, one straight conductive segment) between conductive meshes 1121b, 1121 c, as shown in FIG. 11, some level of redundancy and failuretolerance can be provided. It should be noted that the invention is notlimited to the conductive segment arrangement shown between conductivemeshes 1121 b, 1121 c in FIG. 11, and alternate implementations may beprovided, such as non-straight conductive segments, or more or less thanone conductive segment. In some embodiments, a reduced or minimalconductive segment arrangement is not provided between separatedconductive meshes (e.g., meshes 1121 b and 1121 c) and, instead, asingle, longer mesh is provided to span the gap lacking the resistiveelement (e.g., meshes 1121 b and 1121 c may extended so as to join eachother).

In some embodiments, the nonconductive flexible layer 1103 may be partof a plurality of nonconductive flexible layers 1103, and the conductiveflexible circuit layer 1104 may form part of a plurality of conductiveflexible circuit layers that are interleaved with the plurality ofelectrically nonconductive flexible layers 1104 as described withrespect to various other example embodiments in this disclosure.

In some embodiments, the plurality of electrical loads 1109 may betemperature sensors (e.g., provided at least in part by resistiveelements such as resistive elements 409, 509 609, 709, 809, 909, or1009) and, as described above with respect to FIG. 6, at least the firstelectrical-connection-arrangement 1120 a or the secondelectrical-connection-arrangement 1120 b may electrically connect atleast a respective adjacent pair of temperature sensors by at least onevia (discussed above, e.g., with respect to FIG. 6) arranged toelectrically connect different ones of the plurality of conductiveflexible circuit layers 1104. In some embodiments, the firstelectrical-connection arrangement 1120 a electrically connects therespective adjacent pair of temperature sensors corresponding to thefirst electrical load 1109 a and the second electrical load 1109 b. Insome embodiments, the electrical load 1109 of the plurality ofelectrical loads 1109 is provided at least in part by a respective oneof the plurality of temperature sensors.

FIG. 12 is a schematic plan view of a flexible circuit structure 1201that includes at least an electrically conductive flexible layer 1204formed of electrically conductive material. The electrically conductiveflexible circuit layer 1204 is provided at least proximate to, formed onor in, or supported directly or indirectly by a flexible nonconductivelayer 1203. In some embodiments, the flexible circuit structure 1201includes a plurality of electrical loads 1209 (three called out in FIG.12 as reference symbols 1209 a, 1209 b and 1209 c). In some embodiments,the electrically conductive layer 1204 is patterned to provide aplurality of electrical loads 1209 (three called out in FIG. 12 asreference symbols 1209 a, 1209 b, and 1209 c). The electrical loads 1209are electrically connected in series by a plurality ofelectrical-connection-arrangements 1220 (four called out in FIG. 12 asreference symbols 1220 a, 1220 b, 1220 c and 1220 d), according tovarious embodiments. Each electrical-connection-arrangement 1220electrically connects a respective adjacent pair of electrical loads1209 together, according to some embodiments. In some embodiments, theflexible circuit structure 1201 includes a plurality of measurementleads 1210 (five called out in FIG. 12 as 1210 a, 1210 b, 1210 c, 1210 dand 1210 e), each electrically connected to at least one of theplurality of electrical loads 1209 (e.g., via anelectrical-connection-arrangement 1220) according to some embodiments.In some embodiments, at least some of the measurement leads 1210 areemployed to measure voltage across at least one of the loads and may bealso referred to as electrical-load-voltage-measurement leads 1210. Insome embodiments, at least some of the measurement leads 1210 areemployed to measure current flowing through at least one of the loadsand may be also referred to as electrical-load-current-measurement leads1210. Each of the measurement leads 1210 may be directly connected to arespective electrical-connection-arrangement 1220, according to variousembodiments. In various embodiments, voltage across each of at leastsome of the electrical loads 1209 is sensed or measured at least in partby a respective pair of the measurement leads 1210. It is noted that therespective numbers of electrical loads 1209,electrical-connection-arrangement 1220, and measurement leads 1210 shownin FIG. 12 is non-limiting.

In some embodiments, the flexible circuit structure 1201 includes (e.g.,the conductive flexible layer 1204 may be patterned to include) anelectric-serial-circuitry-connection-arrangement including aserial-electrical-connection order of first measurement lead 1210 a,first electrical load 1209 a, second measurement lead 1210 b, thirdmeasurement lead 1210 c, second electrical load 1209 b, fourthmeasurement lead 1210 d, third electrical load 1209 c, and fifthmeasurement lead 1210 e.

In some embodiments, the electrical-connection-arrangement 1220 b spansa first distance E1 between first electrical load 1209 a and the secondelectrical load 1209 b. The electrical-connection-arrangement 1220 cspans a second distance E2 between second electrical load 1209 b and thethird electrical load 1209 c. In some embodiments, the first distance E1between the first electrical load 1209 a and the second electrical load1209 b is greater than second distance E2 between the second electricalload 1209 b and the third electrical load 1209 c. In some embodiments,the first measurement lead 1210 a and the second measurement lead 1210 bare positioned to sense voltage across the first electrical load 1209 a.In some embodiments, the third measurement lead 1210 c and the fourthmeasurement lead 1210 d are positioned to sense voltage across thesecond electrical load 1209 b. In some embodiments, the fourthmeasurement lead 1210 d and the fifth measurement lead 1210 e arepositioned to sense voltage across the third electrical load 1209 c.

The arrangement of FIG. 12 (as well as the arrangement of FIG. 13,below), where the earlier-described conductive meshes are not providedbetween resistive elements, may be beneficial in some embodiments,because such arrangement may facilitate more accurate measurement orsensing of the resistive elements (e.g., 1209 a, 1209 b, 1209 c), ascompared to embodiments which have more complex connection arrangements.In this regard, some embodiments such as those illustrated in FIG. 12(and FIG. 13, discussed below), may be preferable when fault toleranceof electrical-connection-arrangements 1220 is less of a concern. Ofcourse, the electrical-connection-arrangements 1220 (and 1320 in FIG.13, discussed below) may be replaced with a conductive mesh arrangement,for example, as described above, according to some embodiments.

FIG. 13 shows a schematic plan view of a flexible circuit structure 1301that includes at least an electrically conductive flexible layer 1304formed of electrically conductive material. The electrically conductiveflexible circuit layer 1304 is provided at least proximate to, formed onor in, or supported directly or indirectly by a flexible nonconductivelayer 1303. In some embodiments, the flexible circuit structure 1301includes a plurality of electrical loads 1309 (three called out in FIG.13 as reference symbols 1309 a, 1309 b and 1309 c). In some embodiments,the electrically conductive layer 1304 is patterned to provide aplurality of electrical loads 1309 (three called out in FIG. 13 asreference symbols 1309 a, 1309 b and 1309 c). The electrical loads 1309are electrically connected in series by a plurality ofelectrical-connection-arrangements 1320 (four called out in FIG. 13 asreference symbols 1320 a, 1320 b, 1320 c and 1320 d) according tovarious embodiments. Each electrical-connection-arrangement 1320electrically connects a respective adjacent pair of electrical loads1309 together according to some embodiments. In some embodiments, theflexible circuit structure 1301 includes a plurality of measurementleads 1310 (five called out in FIG. 13 as 1310 a, 1310 b, 1310 c, 1310 dand 1310 e), each electrically connected to at least one of theplurality of electrical loads 1309 (e.g., via anelectrical-connection-arrangement 1320) according to some embodiments.In some embodiments, at least some of the measurement leads 1310 areemployed to measure voltage across at least one of the loads and may bealso referred to as electrical-load-voltage-measurement leads 1310. Insome embodiments, at least some of the measurement leads 1310 areemployed to measure current flowing through at least one of the loadsand may be also referred to as electrical-load-current-measurement leads1310. Each of the measurement leads 1310 may be directly connected to arespective electrical-connection-arrangement 1320 according to variousembodiments. In various embodiments, voltage across each of at leastsome of the electrical loads 1309 is sensed or measured at least in partby a respective pair of the measurement leads 1310. It is noted that therespective numbers of electrical loads 1309,electrical-connection-arrangement 1320, and measurement leads 1310 shownin FIG. 13 is non-limiting.

In some embodiments, a first pair of leads 1310 a, 1310 b of theplurality of measurement leads 1310 is positioned to sense voltageacross the first electrical load 1309 a of the plurality of electricalloads 1309. A second pair of leads 1310 b, 1310 c of the plurality ofmeasurement leads 1310 is positioned to sense voltage across the secondelectrical load 1309 b of the plurality of electrical loads 1309. Athird pair of leads 1310 d, 1310 e of the plurality of measurement leads1310 is positioned to sense voltage across the third electrical load1309 c of the plurality of electrical loads 1309.

In some embodiments, the first electrical load 1309 a is adjacent to thesecond electrical load 1309 b in the series and the second electricalload 1309 b and the third electrical load 1309 c are adjacent in theseries. According to some embodiments, the first pair of leads 1310 a,1310 b and the second pair of leads 1310 b, 1310 c include a same lead1310 b of the plurality of measurement leads 1310. According to someembodiments, the second pair of leads 1310 b, 1310 c does not includeany of the plurality of measurement leads 1310 of the third pair ofleads 1310 d, 1310 e.

In some embodiments, a distance F1 spanning the first electrical load1309 a and the second electrical load 1309 b is different than adistance F2 spanning the second electrical load 1309 b and the thirdelectrical load 1309 c. In some embodiments, the distance F2 spanningthe second electrical load 1309 b and the third electrical load 1309 cis greater than the distance F1 spanning the first electrical load 1309a and the second electrical load 1309 b. In some embodiments, a distanceF1 separating the first electrical load 1309 a from the secondelectrical load 1309 b is different than a distance F2 separating thesecond electrical load 1309 b from the third electrical load 1309 c. Insome embodiments, the distance F2 separating the second electrical load1309 b from the third electrical load 1309 c is greater than thedistance F1 separating the first electrical load 1309 a from the secondelectrical load 1309 b.

In some embodiments, an electrical resistance of a conductive portion(e.g., electrical-connection-arrangement 1320 b) of the flexible circuitstructure 1301 that serially electrically connects the first electricalload 1309 a to the second electrical load 1309 b is different than anelectrical resistance of a conductive portion (e.g.,electrical-connection-arrangement 1320 c) of the flexible circuitstructure 1301 that serially electrically connects the second electricalload 1309 b to the third electrical load 1309 c. In some embodiments,the electrical resistance of the conductive portion of the flexiblecircuit structure 1301 that serially electrically connects the secondelectrical load 1309 b to the third electrical load 1309 c is greaterthan the electrical resistance of the conductive portion of the flexiblecircuit structure 1301 that serially electrically connects the firstelectrical load 1309 a to the second electrical load 1309 b. Forexample, in various embodiments, the conductive portion of the flexiblecircuit structure 1301 that serially electrically connects the secondelectrical load 1309 b to the third electrical load 1309 c may beprovided by a patterned electrical conductive structure that has arelatively longer length in order to span the distance F2 and willthereby typically cause the portion of the flexible circuit structurethat serially electrically connects the second electrical load 1309 b tothe third electrical load 1309 c to have a greater electrical resistancethan the electrical resistance of the “relatively shorter” conductiveportion of the flexible circuit structure 1301 that seriallyelectrically connects the first electrical load 1309 a to the secondelectrical load 1309 b over the relatively shorter distance F1. In someembodiments, each of at least some of the conductive portions of theflexible printed circuit structure 1301 that serially electricallyconnect the members of a respective adjacent pair of the electricalloads 1309 is provided by a single conductive segment.

In some embodiments, the conductive portions of the flexible printedcircuit structure 1301 that serially electrically connect the members ofa respective adjacent pair of the electrical loads 1309 are eachprovided by a respective one of the electrical-connection-arrangements1320 that at least directly connect, electrically connect, or bothdirectly and electrically connect the respective adjacent pair ofelectrical loads 1309 of the plurality of electrical loads.

Although each of FIGS. 12 and 13 illustrateselectrical-connection-arrangements 1220, 1320 as single connection linesor electrical pathways, such electrical-connection-arrangements mayinstead take the form of, or include, any conductive mesh describedherein (e.g., 420, 520, 620, 720, 820, 920, 1020, or 1120) or otherwisewithin the scope of the present invention. In this regard, at least someof the plurality of electrical-connection-arrangements 1220, 1320 mayinclude a set of one or more conductive meshes, each conductive meshincluding a plurality of conductive segments spatially arranged toprovide a plurality of electrical pathways defining a respective portionof an electric current flow path between the electrical loads (e.g.,1209, 1309) of a respective adjacent pair of electrical loads. Eachconductive segment may provide a respective portion of the plurality ofelectrical pathways. Each of at least some of conductive meshes may bedirectly connected to one or more of the plurality of measurement leads(e.g., 1210, 1310) according to some example embodiments.

FIG. 16 is a block diagram of an electrical circuit 1600 that is atleast configured to measure or determine voltage or current, accordingto some embodiments. Such a circuit 1600 may be incorporated into themedical device system of FIG. 1, 3A, or 3B, or more particularly, into atransducer-based device system (e.g., 200 or 300), and connected to thevarious measurement leads 1610, such as those described herein (e.g.,410, 510, 610, 710, 810, 1110, 1210, 1310) or otherwise within the scopeof the present invention. As discussed above, the resistive elements(e.g., 1609), transducers 1602, and other structures of FIG. 16 maycorrespond to the same or different embodiments of such elements andstructures described above with respect to FIG. 4 or any other figureherein including such elements and structures, according to someembodiments.

Electrical circuit 1600 is configured, according to some embodiments, todetermine an electrical resistance of various resistive elements 1609employed by various transducers (e.g., FIG. 4) 1602 a, 1602 b, . . .1602 n (collectively 1602) which may be positioned in a bodily cavity(e.g., left atrium 204) including one or more ports (e.g., pulmonaryvein ostia or a mitral valve 226) in fluid communication with the bodilycavity. In some embodiments, a portion (e.g., an electrode surface or aportion thereof) of a first transducer 1602 may be positioned in contactwith non-fluidic tissue (e.g., cardiac tissue) while a portion (e.g., anelectrode surface or a portion thereof) of a second transducer 1602 maybe in contact with fluidic tissue (e.g., blood). The number oftransducers 1602 employed may vary in different embodiments.

Each resistive element 1609 may be formed from copper traces on aflexible printed circuit board substrate (e.g., resistive elements 409,509, 609, 709, 809, 909, 1009, 1109, 1209, 1309), or resistive elementsprovided on a structure. Each transducer 1602 is driven by a statemachine within a controller (e.g., controller 324), according to someembodiments. In various embodiments, electrical circuit 1600 includes asignal source device system 1612 and a sensing device system 1616, eachschematically distinguished from one another by a broken line in FIG.16. It is understood that one or both of signal source device system1612 and sensing device system 1616 may each include different circuitrythan those shown in FIG. 16. In various embodiments, signal sourcedevice system 1612 provides various input signals to at least some ofthe transducers 1602 during a temperature sensing mode. In someembodiments, signal source device system 1612 provides various inputsignals to at least some of the transducers 1602 during a flow sensingmode (described below). In some example embodiments, signal sourcedevice system 1612 provides various input signals to each of thetransducers 1602 during a mapping mode in which information specifying alocation of various anatomical features within a bodily cavity isgenerated (e.g., by convective cooling of heated transducer elements byfluid as described above in this disclosure). Information specifying alocation of each of one or more regions of an interior tissue surfacewithin a bodily cavity may be provided along with information specifyinga location of each of at least one of one or more ports on the interiortissue wall with respect to the one or more regions during the mappingmode. In some example embodiments, signal source device system 1612provides various input signals to each of the transducers 1602 during atissue contact mode in which assessment of contact or an amount ofcontact between a portion (e.g., an electrically conductive surfaceportion of an electrode) of each of the various transducers 1602 andnon-fluidic tissue or a fluidic tissue is made. In some exampleembodiments, signal source device system 1612 provides various inputsignals during an ablation mode. In some example embodiments, a statemachine in the controller (e.g., controller 324) may be employed tocause various control signals to be provided to signal source devicesystem 1612 to configure electrical circuit 1600 in at least one of atemperature sensing mode and a flow sensing mode. In some exampleembodiments, signal source device system 1612 includes a radio-frequencygenerator configured to transfer energy to, or from, the tissue wall. Insome example embodiments, the radio-frequency generator is arranged toprovide a varying electric current to at least one of the transducers1602 to provide energy to tissue from the at least one of thetransducers 1602.

In various embodiments, digital-to-analog converter (DAC) 1614 generatesan input signal that is amplified and is driven across the series of theconnected resistive elements 1609 during a temperature sensing mode.Amplifiers including driver 1615 a and driver 1615 b are arranged toproduce a balanced output across the series of connected resistiveelements 1609. Electric current driven through resistive elements 1609is sampled by sensing device system 1616. In this example embodiment,electric current driven through resistive elements 1609 is sampled inseries with each of the drivers 1615 a, 1615 b via respective ones ofanalog-to-digital converters (ADC) 1618 a, 1618 b. It is noted thatsensing the electric current at each of the drivers 1615 a, 1615 b canallow the system to detect possible failures that may result in theelectric current leaking through another path. Voltage across each ofthe resistive elements 1609 is also sampled by sensing device system1616 via respective ones of analog-to-digital converters (ADC) 1619(three called out in FIG. 16). In some embodiments, the current andvoltage measurements are sampled synchronously with the input signal andthe demodulation of each measurement is computed by the controller.Electrical circuit 1600 allows for the electrical resistance of each ofthe resistive elements 1609 to be precisely determined. The resistanceof an electrically conductive metal (e.g., copper) changes based on thetemperature of the electrically conductive metal. The rate of change isdenominated as a temperature coefficient of resistance (TCR). Theresistance of various ones of the resistive elements 1609 may be relatedto the temperature of the resistive element 1609 by the followingrelationship:R=R ₀*[1+TCR*(T−T ₀)], where:

R is a resistance of the electrically conductive metal at a temperatureT;

R₀ is a resistance of the electrically conductive metal at a referencetemperature T₀;

TCR is the temperature coefficient of resistance of the electricallyconductive metal for the reference temperature (i.e., the TCR for copperis 4270 ppm at T₀=0° C.); and

T is the temperature of the electrically conductive metal.

When signal source device system 1612 applies energy to a resistiveelement (e.g., resistive element 1609 employed by various transducers1602) positioned within a medium having relatively high flow conditions(e.g., when subjected to blood flow conditions proximate a pulmonaryvein port in the left atrium of a heart or when not shielded from theflow by contact with non-fluidic tissue), the resistive element willreach a lower temperature and will settle more quickly than if theresistive element were positioned within a medium having relatively lowflow conditions (e.g., when positioned proximate, or in contact with aregion of a non-fluidic tissue surface within a left atrium positionedaway from a pulmonary vein port). Likewise, when the signal sourceceases to apply energy, the resistive element positioned within a mediumhaving relatively high flow conditions will cool faster and will returnto ambient temperature faster than if the resistive element were to bewithin a medium having relatively lower flow conditions. When the signalsource repetitively applies and ceases to apply energy to the resistiveelement, the resulting temperature changes of the resistive elementpositioned in a medium having relatively low flow conditions will appearto have a phase delay compared to the resulting temperature changes ofthe resistive element when positioned in a medium having relativelyhigher flow conditions.

In various embodiments, flow sensing is provided by electrical circuit1600 by determining the rate of convective cooling at various ones ofthe resistive elements 1609. In some embodiments, when the flow sensingmode is enabled, various ones of the resistive elements 1609 whosetemperature is determined during the temperature sensing mode may alsobe employed to deliver energy (i.e., heat) during the flow sensing mode.In various embodiments, the energy is delivered using the same drivers1615 a, 1615 b employed in the temperature sensing mode. It isunderstood that additional and or alternate drivers may be employed inother example embodiments but with additional cost and complexity. Whenthe temperature sensing mode is not active, the controller system maycontinue to drive an input signal to each of the resistive elements 1609in various embodiments. In some embodiments, the temperature sensingmode is employed to sense temperature at least during an ablation modein which tissue proximate at least a particular one of the resistiveelements 1609 is ablated.

Subsets or combinations of various embodiments described above providefurther embodiments.

These and other changes may be made to various embodiments in light ofthe above-detailed description. In general, in the following claims, theterms used should not be construed to limit the invention to thespecific embodiments disclosed in the specification and the claims, butshould be construed to include other transducer-based device systemsincluding all medical treatment device systems and all medicaldiagnostic device systems in accordance with the claims. Further, itshould be noted that, although several of the above-discussedembodiments are described within the context of an intra-cardiac medicaldevice system, other embodiments apply to other medical and non-medicaldevice systems, such as a device system in which detecting or providingtolerance for one or more improper energy transmission configurations isbeneficial. Accordingly, the invention is not limited by thisdisclosure, but instead its scope is to be determined entirely by theclaims.

What is claimed is:
 1. A flexible circuit structure comprising: at leastone nonconductive flexible layer comprising an electrically insulativematerial; and one or more conductive flexible circuit layers proximatethe at least one nonconductive flexible layer, each of the one or moreconductive flexible circuit layers comprising an electrically conductivematerial, wherein the one or more conductive flexible circuit layerscomprises or comprise: a first electrical-connection-arrangement; afirst adjacent pair of electrical loads electrically connected in seriesby the first electrical-connection-arrangement, the firstelectrical-connection-arrangement directly connecting a first electricalload of the first adjacent pair of electrical loads to a secondelectrical load of the first adjacent pair of electrical loads; and afirst electrical-load-measurement lead electrically connected to thefirst electrical-connection-arrangement, wherein the firstelectrical-load-measurement lead comprises a first branched structurecomprising a first plurality of conductive branches, each conductivebranch of the first plurality of conductive branches electricallyconnected to the first electrical-connection-arrangement at a respectiveone of a first plurality of electrical connection points.
 2. Theflexible circuit structure of claim 1, wherein the flexible circuitstructure comprises a plurality of electrical-connection-arrangementsand a plurality of electrical loads electrically connected in series bythe plurality of electrical-connection-arrangements, eachelectrical-connection-arrangement of the plurality ofelectrical-connection-arrangements electrically connecting a respectiveadjacent pair of electrical loads of the plurality of electrical loads,the plurality of electrical-connection-arrangements comprising the firstelectrical-connection-arrangement, and the plurality of electrical loadscomprising the first adjacent pair of electrical loads.
 3. The flexiblecircuit structure of claim 1, further comprising: a secondelectrical-connection-arrangement electrically connected to a firstelectrical load of the first adjacent pair of electrical loads; and asecond electrical-load-measurement lead electrically connected to thesecond electrical-connection-arrangement, the firstelectrical-load-measurement lead and the secondelectrical-load-measurement lead arranged to measure voltage across thefirst electrical load.
 4. The flexible circuit structure of claim 3,wherein the second electrical-load measurement lead comprises a secondbranched structure comprising a second plurality of conductive branches,each conductive branch of the second plurality of conductive brancheselectrically connected to the second electrical-connection-arrangementat a respective one of a first plurality of electrical connectionpoints.
 5. The flexible circuit structure of claim 4, wherein the numberof conductive branches of the second plurality of conductive branches isdifferent than the number of conductive branches of the first pluralityof conductive branches.
 6. The flexible circuit structure of claim 1,wherein the first electrical-connection-arrangement comprises one ormore conductive meshes, each conductive mesh including a plurality ofconductive segments spatially arranged to provide a plurality ofelectrical pathways defining a respective portion of an electric currentflow path, the respective portion of the electric current flow pathlocated between the electrical loads of the first adjacent pair ofelectrical loads, and each conductive segment of the plurality ofconductive segments providing a respective portion of the plurality ofelectrical pathways.
 7. The flexible circuit structure of claim 1,wherein the at least one nonconductive flexible layer comprises aplurality of electrically nonconductive flexible layers, and the one ormore conductive flexible circuit layers comprises a plurality ofconductive flexible circuit layers that are interleaved with theplurality of electrically nonconductive flexible layers.
 8. The flexiblecircuit structure of claim 1, wherein each electrical load of the firstadjacent pair of electrical loads comprises a resistive element.
 9. Theflexible circuit structure of claim 8, wherein each resistive elementcomprises a serpentine form.
 10. The flexible circuit structure of claim1, wherein each electrical load of the first adjacent pair of electricalloads is a resistive element, wherein the one or more conductiveflexible circuit layers comprises a plurality of conductive flexiblecircuit layers, and wherein at least the firstelectrical-connection-arrangement electrically connects at least anadjacent pair of the resistive elements by at least one via arranged toelectrically connect different ones of the plurality of conductiveflexible circuit layers.
 11. The flexible circuit structure of claim 1,wherein each electrical load of the first adjacent pair of electricalloads is a temperature sensor, wherein the one or more conductiveflexible circuit layers comprises a plurality of conductive flexiblecircuit layers, and wherein at least the firstelectrical-connection-arrangement or the secondelectrical-connection-arrangement electrically connects at an adjacentpair of the temperature sensors by at least one via arranged toelectrically connect different ones of the plurality of conductiveflexible circuit layers.
 12. The flexible circuit structure of claim 1,wherein each electrical load of the first adjacent pair of electricalloads is provided at least in part by a respective one of a pair oftemperature sensors.
 13. The flexible circuit structure of claim 1,wherein the at least one nonconductive flexible layer comprises aplurality of nonconductive flexible layers, and wherein the flexiblecircuit structure comprises a plurality of electrodes, each electrode ofthe plurality of electrodes arranged in an overlapping relationship witha respective electrical load of the first adjacent pair of electricalloads, and wherein at least a first nonconductive flexible layer of theplurality of nonconductive flexible layers is located between theplurality of electrodes and the first adjacent pair of electrical loads.